[HN Gopher] A guide to learning algorithms through LeetCode
___________________________________________________________________
A guide to learning algorithms through LeetCode
Author : VitalyAnkh
Score : 253 points
Date : 2020-08-15 09:11 UTC (1 days ago)
(HTM) web link (github.com)
(TXT) w3m dump (github.com)
| bradlys wrote:
| Gosh, I don't enjoy that there is so much competition in this
| space. I can't compete against people who essentially seem to
| have no life or other interests than getting job at Big N (or
| enjoy competitive programming).
|
| It feels like this culture has ramped up in the last 5-10 years.
| When I started interviewing, the questions were easier. It feels
| like they've gotten more difficult - or at least the answer the
| interviewer wants is less attainable.
|
| And I feel like I know why - go look at the leetcode discussion
| forums. There's almost always some post at the top saying, "I did
| 1000 problems and won't stop. I got accepted/rejected and learned
| so much. Believe." From the outside and inside, it looks like a
| cult. I feel like these folks are just making it worse for
| everyone.
|
| Maybe I am just bitter because I've passed every mock interview
| I've done but I can't get an offer from Big N still. Startups are
| the worst as a non-founder/non-executive.
| [deleted]
| PragmaticPulp wrote:
| > I can't compete against people who essentially seem to have
| no life or other interests than getting job at Big N (or enjoy
| competitive programming).
|
| Interview prep doesn't need to be a grind. One of the nice
| things about Leetcode is that the problems are bite-sized. You
| can do one or two per day on your lunch break and make a lot of
| progress in a matter of months, or even weeks.
|
| Don't approach it like a cram session before your interviews.
| That doesn't work unless maybe you're a new college grad with
| no other obligations.
|
| > go look at the leetcode discussion forums. There's almost
| always some post at the top saying, "I did 1000 problems and
| won't stop.
|
| Obviously the Leetcode forums are going to be a hotbed of
| discussion about Leetcode. You have to keep in mind that many
| of those people are entry-level developers treating this as an
| extension of their education. For them, it's basically a
| miracle that a mostly-free website lets them practice for
| interviews for $200K-300K+ career paths from the comfort of
| their web browser. Compare that to just about any other high-
| paying industry, where getting the right education,
| credentials, certifications, and test results will take years
| of your life and potentially hundreds of thousands of dollars
| of post-secondary education. We really have the easy end of
| this deal.
|
| Don't let the total number of Leetcode questions overwhelm or
| discourage you. It shouldn't be approached as a cram session
| before the interview. It should be approached as a consistent
| habit or practice over a longer period of time.
|
| If you just don't want to do any Leetcode or whiteboard
| interviews, that's fine too! There are plenty of jobs out there
| that won't require any of that.
|
| However, you can't have it both ways: Big N salaries come with
| a high barrier to entry. All things considered, spending 50-100
| hours of your free time solving problems on a free website at
| your leisure is really a small price to pay.
| bradlys wrote:
| > All things considered, spending 50-100 hours of your free
| time solving problems on a free website at your leisure is
| really a small price to pay.
|
| The problem is - it's not 50-100 hours for most candidates to
| pass. I've done well past 400 hours of interview prep and
| never received an offer from Big N. I tried the consistent
| 1-hour or so a day for months thing - it isn't guaranteed
| either. Want to emphasize this point to - it isn't like I
| can't do the problems. I've solved most any problem I'm given
| - it's that it just doesn't fucking matter. Whatever bias the
| person has is what they will evaluate on - the problem
| solving is merely a formality.
| PragmaticPulp wrote:
| No one is guaranteed a job at Big-N companies.
|
| It's important to understand that Big-N job offers or
| rejections aren't a perfect indicator of a person's
| programming ability.
|
| The interview process isn't perfect. It's not designed to
| be perfect, because that's an impossible goal. In reality,
| Big-N companies have so many applicants that some of them
| have higher rejection rates than Ivy League universities.
|
| At this scale, the goal isn't to admit any and every
| qualified candidate. The goal is to select for the best of
| the best and minimize false positives, even if it results
| in a large number of false negatives.
| nulptr wrote:
| I don't think it's just about solving the problem.
|
| It's also about: - how you convinced yourself and the
| interviewer that your solution was correct (essentially an
| informal proof of your code) - how you test
| your code after you finish coding - what
| clarifying questions you asked to tease out a concrete
| question - what edge cases you thought of and
| how you handled them - how you handle bugs if
| they appear in the code - what solutions you
| presented and what their tradeoffs were, and why you
| decided to use a particular solution - whether
| your code was idiomatic - whether you used clean
| abstractions - maybe also comments and variable
| naming
|
| ... and probably others I'm missing.
|
| I don't deny that interviewers have their biases, but I
| would hope that your interview performance is the major
| factor in whether you received an offer. There are plenty
| of people at Google and Facebook who haven't majored in CS
| at a top school.
| noema wrote:
| From talking to some people who give out these
| interviews, most of those points really don't matter at
| all. What matters is A) getting a correct solution and B)
| being able to explain how you arrived at the solution.
| Tests, idiomatic code, clean design, etc are not expected
| and will inevitably waste precious time. Besides, the
| very nature of the interview (using a walled-off in-
| browser pseudo-IDE) restricts you from actually writing
| best-practice code.
| doc_gunthrop wrote:
| All the items are taken from Leetcode problems, but for the vast
| majority of them the author (labuladong) does not give
| attribution.
|
| There should at least be a link to the related Leetcode problem
| for each section.
| pcestrada wrote:
| Can you imagine having to learn all this just to make a
| connection to a database, process some data, and then persist it
| somewhere?
| PragmaticPulp wrote:
| The popular sentiment on computer science knowledge has done a
| complete 180 in the past several years.
|
| Not that long ago, it was popular to complain that junior SWEs
| didn't really understand the algorithms, the data structures,
| and what was going on behind the scenes. The complaint was that
| they were just copy and pasting from internet searches until
| things sort of worked on their machine, but they couldn't
| recognize when an O(n^2) solution was going to work on their
| local n=10 test set but bring down the main website.
|
| Now that knowledge of CS fundamentals has become valued in
| interviews, the pendulum has swung the opposite way. We have
| more free resources than ever before to practice and study CS
| fundamentals, algorithmic challenges, and even practice your
| interview skills. It's never been easier for a junior SWE to
| sit down, put in the effort, and work their way into a
| $200-300K job with sufficient dedication. Yet people never tire
| of complaining about Leetcode or having to understand CS
| fundamentals online.
|
| Personally, I've never met anyone who was good at Leetcode yet
| produced bad code in production. I'm sure there's someone out
| there who knows a guy who knows a guy who can somehow ace
| Leetcode but can't write an efficient website backend, but it's
| not the norm.
| lawn wrote:
| > Personally, I've never met anyone who was good at Leetcode
| yet produced bad code in production.
|
| I competed with this guy in competitive programming
| competitions and while he was fantastic at it, he wrote the
| worst code I've ever seen.
|
| I've also worked with many people who've never even heard of
| Leetcode or similar and they were fantastic developers.
|
| In my opinion there's no correlation here and it's purely a
| distraction.
| bcrosby95 wrote:
| > Personally, I've never met anyone who was good at Leetcode
| yet produced bad code in production. I'm sure there's someone
| out there who knows a guy who knows a guy who can somehow ace
| Leetcode but can't write an efficient website backend, but
| it's not the norm.
|
| Weird. Ability to leetcode doesn't mean you know what is
| happening in e.g. an RDBMS. We've had people good at leetcode
| write a single query to delete hundreds of millions of
| records in a table with billions of records that was being
| constantly updated by the live website. Needless to say it
| didn't go over well. Ability to leetcode doesn't give you any
| knowledge that doing so might be a bad idea.
| xfer wrote:
| You can learn how to use some function to call into a
| database and study its behaviour, if you can grind leetcode
| and solve problems.
|
| It's a good enough filter, the alternative is either way
| more costly or way worse(if you have seen "interviewing"
| which are just thinly veiled nepotism).
| anon349852034 wrote:
| > Personally, I've never met anyone who was good at Leetcode
| yet produced bad code in production.
|
| It's all anecdotal evidence. I've worked with some brilliant
| people at most places I've been and I can't think of 1 person
| who even had LeetCode account. Producing great production
| code is more about experience and knowledge of the domain
| than knowing how to bang out algorithms.
| [deleted]
| PragmaticPulp wrote:
| > I've worked with some brilliant people at most places
| I've been and I can't think of 1 person who even had
| LeetCode account.
|
| That's not the point, though. No one said that Leetcode is
| mandatory for being a good programmer.
|
| The point is that Leetcode, however imperfect, is still a
| usable signal for programming ability.
|
| Those excellent programmers you know would likely not have
| much difficulty with Leetcode style problems if they were
| to try them. That's the point.
| yodsanklai wrote:
| > I'm sure there's someone out there who knows a guy who
| knows a guy who can somehow ace Leetcode but can't write an
| efficient website backend
|
| I don't see what makes you think a person who can ace
| Leetcode should be able to write an "efficient website
| backend". These are different sets of skills. You can ace
| Leetcode and not even know what a backend is.
|
| > knowledge of CS fundamentals
|
| Leetcode is not CS fundamentals. It's a small part of CS
| fundamentals. Besides, candidates aren't asked to show they
| know the CS fundamentals. They are asked to show that they
| spent more time practicing leetcode than the other guys.
| dbuser99 wrote:
| Leetcode is not a good indicator of quality code by any
| means. It's basically a filter. If one can't solve these
| programming questions, there is a higher chance that they are
| not good at programming compared to one who can.
| tourist_on_road wrote:
| But it might come handy when implementing - route optimization
| problems - Building database query optimization engine
|
| You can argue that not everyone is implementing these from
| scratch every day. But it could be argued that given an
| opportunity, an engineer should have the skills and ability to
| build these systems.
| jkachmar wrote:
| Bullshit.
|
| It has been my personal experience, and the experience of
| many people I've spoken with, that this kind of trivia is
| learned in order to get a job and then forgotten immediately
| afterwards because it's useless.
|
| Anecdotal example: a former colleague is an incredibly
| talented systems programmer and has had to study leetcode
| garbage for the last few months in order to feel qualified to
| interview for a position with a team that he had previously
| been on at an older employer.
|
| As another commenter said elsewhere, these types of questions
| are used because they're legal proxies for "IQ tests", and
| because they filter for people who are willing to sacrifice
| much of their personal time for the sake of the company.
| biztos wrote:
| I don't think the knowledge is _useless_ as much as it 's
| properly abstracted away into core libraries for 99.999% of
| the real-world use-cases.
|
| Maybe the questions started as "IQ tests" (or a proxy for
| "fresh out of a Stanford-like CS Program?") but my
| impression is that now it's a mild (or not) proxy for
| hazing.
|
| "I suffered through this crap and by God you are going to
| suffer through it to, or you can't join my little club, and
| by the way I just make a hundred dollars telling you that."
|
| Edit: clarity & speling
| jkachmar wrote:
| I think knowledge of the concepts is very useful, but
| precise recall of the algorithmic implementations is
| absolutely useless.
|
| It's very different for someone to have a solid grasp of,
| say, cache-aware programming techniques, algorithms and
| data structures that are necessary for low-latency
| architectural work, etc.
|
| ...but I'm aware of very few positions (if any???) that
| require the ability to arbitrarily synthesize that
| information on the spot.
|
| EDIT: Originally meant to lead with the fact that I
| broadly agree with what you're saying, I just wanted to
| clarify my original objection.
| [deleted]
| bcrosby95 wrote:
| > But it could be argued that given an opportunity, an
| engineer should have the skills and ability to build these
| systems.
|
| Having the skills and ability to build these systems doesn't
| mean you can regurgitate all the algorithms required to build
| them on a whiteboard in 30-60 minutes. It means you have to
| ability to search for algorithms and apply them to your
| problem at hand over the course of several days, weeks, or
| even months.
|
| Do you really think anyone building these systems spent only
| 60 minutes both deciding upon, and coding ANY of their
| algorithms and called it a day because they obviously chose
| the best one?
| tourist_on_road wrote:
| Isn't it what computer science is all about. You won't
| necessarily see the exact problem. But having the ability
| to reduce the problem at hand to an efficient algorithm
| that you might have "regurgitated".
| [deleted]
| person_of_color wrote:
| Is this evidence of the 996 culture?
| mjburgess wrote:
| 996 is a universal culture.
|
| People who wish to master a skill on their own time are simply
| pursuing an intrinsic (/identity-based) goal: here, excellence
| in computer science.
| flak48 wrote:
| Evidence of Leetcode culture more than anything
| throwaway_pdp09 wrote:
| FYI https://en.wikipedia.org/wiki/996_working_hour_system
|
| "The 996 working hour system is a work schedule commonly
| practiced by some companies in the People's Republic of China.
| It derives its name from its requirement that employees work
| from 9:00 am to 9:00 pm, 6 days per week"
| cheez wrote:
| Looks more like tech interview culture.
| digianarchist wrote:
| It's becoming obvious to me that my time is better spent learning
| to solve these riddles rather than actually becoming a better
| developer. I have a job search coming up at the end of the year
| and whilst I've managed to largely avoid companies that ask this
| type of question, I believe it's seriously constraining my
| career.
|
| I can't speak for everyone but the whiteboard interview has
| prevented me from leaving jobs earlier, moving jobs more
| frequently and left me avoiding certain companies altogether.
| anon349852034 wrote:
| I have 2 friends who work at the Amazon office in Denver. Both
| work on boring projects utilizing internal tools Amazon built
| over the years and completely hate their lives. But the salary
| and stock options make them stick around. You can look at this
| as "Omg, this is total shit. I'd never want to work here." or
| "I don't mind suffering 4 years to get fully vested, get the
| fuck out of dodge and enjoy retirement a little earlier than
| others." Both of my friends picked the latter.
| lowiqengineer wrote:
| I'm gonna take a wild guess and say that if it was Google
| they wouldn't have that opinion, eh?
| grumple wrote:
| I wonder if that isn't the point, to increase developer
| retention and reduce competition for devs.
| fractionalhare wrote:
| That could be part of it, but I don't think it's the primary
| reason. Rather I believe it's just one example of a more
| general, emergent phenomenon in capitalism, in which the top
| decile of jobs in high paying careers converge to interview
| methods which are a legal proxy for IQ testing.
|
| It is a game of cat and mouse between candidates and
| companies. The candidates want high pay and interesting work,
| and the companies want only the top n% of candidates for
| their work, for some metric of their choosing. However many
| candidates a company has to choose from, they will devise
| some way of choosing the best among them. The methods for
| determining the best become (in my opinion) increasingly
| pathological as the surplus of candidates increases. In tech,
| the result is that the past decade has seen a supermajority
| of the most lucrative, mainstream jobs moving to a local
| maximum: whiteboard interviews based on data structures and
| algorithms. In response, candidates have gamified the process
| of studying for these metrics using Leetcode, and so a
| cottage industry of adult test prep was born.
|
| Other industries use extreme credentialism or other methods
| to cut down on the vast majority of resumes they see, and
| there likewise emerges a cottage industry of professional
| preparation to break into these careers at the highest level.
| The companies use these methods because they see an absolute
| glut of candidates and become risk averse to bad hires -
| because after all, if they can attract so much talent with
| high pay and prestige, why should they suffer possible duds?
| This is how we end up with the, "Google is okay with passing
| on false negatives but can't tolerate a false positive in
| their hiring process" reasoning.
| lowiqengineer wrote:
| It's funny/depressing to think all of my depression stems
| from not being able to do these problems fluently.
| rightbyte wrote:
| It would be a "tragedy of the commons"-like effect for
| companies that don't adhere. I would guess that is just an
| unintended effect and that there is no master plan behind
| making recruiting expensive, slow and inaccurate.
| jdietrich wrote:
| Or it's part of an organised cartel between the major SV
| employers to reduce salary competition and employee
| turnover.
|
| https://en.wikipedia.org/wiki/High-
| Tech_Employee_Antitrust_L...
| an_opabinia wrote:
| Surely the generous pay is the biggest factor for retention?
|
| Competition is ill defined in the labor market because people
| aren't fungible. So it's hard to really point to hard
| evidence, so and so practice leads to so and so change in
| salaries or increase in retention.
|
| Aside, nobody said this guy was looking for a low paying job.
| High paying ones want leetcode.
|
| Google will pay a higher salary to a 21 year old than a Miami
| firm will pay to someone with 10 years of experience. Nobody
| will ask you these puzzles outside of ~5 markets in the US.
| They also pay way less.
| benrbray wrote:
| Anecdotally I would say job satisfaction is at least as
| important a factor in retention, at least until employees
| are old enough to have started a family.
|
| Many young people (age 20-30) I know are in a situation
| where they are paid large sums of money ($100k-$200k) for
| extremely dull work. I've seen most of my friends from
| college quit their FAANG job in search of something more
| fulfilling, often at a 50% or more pay cut.
| cactus2093 wrote:
| Kind of a meta point, but why do you call it the whiteboard
| interview? I think that was more popular 5 to 10 years ago,
| actually writing code or pseudocode on a whiteboard. In my
| experience the leetcode style questions most companies use
| today have you actually write and execute code in a sandbox
| environment.
|
| It may be that the algorithms you're required to come up with
| are still overkill in that they're things you would not
| normally need to write from scratch on the spot without being
| able to references any resources in your day to day work. But
| as far as the format goes, this style of actually writing and
| executing code is clearly an improvement on the write-code-on-
| whiteboard style of interview.
|
| I feel your pain though, the weeks of study that almost any
| good engineer needs to put into preparing for interviews can be
| pretty grueling.
| mettamage wrote:
| According to the believers it is an unbiased way of predicting
| whether people are capable for the job. Google has done a lot
| of tests and these style of interviews predict job performance
| best [1].
|
| Assuming this is true then to me it means that universities and
| work experience are too heterogeneous as a measure of job
| performance.
|
| In my experience that is true. Not sure how well the argument
| holds up if everyone is simply going to study algorithms
| though.
|
| [1] clement mihailescu says it on his YT channel somewhere in a
| vid.
| username90 wrote:
| If you work at google you can go find those studies yourself,
| they are public internally. At least you could when I worked
| there.
| logicslave12 wrote:
| I was working on a "startup"/kinda just unemployed for two
| years. I studied leetcode hard, and got hired into a 300k a
| year job at FAANG. I know nothing about testing, git, software
| process, roll outs, dev ops, etc. I barely know how to do
| software engineering. What an idiotic hiring process.
| [deleted]
| sukilot wrote:
| Do you think it's unlikely for you to learn those skills
| quickly? People who have all those skills earn over $300K at
| those companies.
| wdb wrote:
| My experience of FAANG interviews outside the US is that
| the salaries they offer are really disappointing compared
| to the US. Other industries like finance were a better deal
| compared those companies. If I can get paid PS90-110k in
| the City why bother working for Facebook were they were
| offering less than PS90k? Note, I don't consider bonuses or
| equity to part of salary.
| andreilys wrote:
| " Note, I don't consider bonuses or equity to part of
| salary."
|
| Depending on the company and how much the stock
| appreciates this can easily be +50% of your total take
| home so I'm not sure why you'd discount it.
| thewarrior wrote:
| Why would equity or bonuses not be part of the salary ?
| You are almost certain to receive it and the stocks
| perform quite well on average.
|
| They still pay better than finance all things taken
| together or am I wrong ?
| qppo wrote:
| > Note, I don't consider bonuses or equity to part of
| salary.
|
| Tell that to the tax man
| biztos wrote:
| To be fair, a lot of people who have none of those skills
| also earn well over $300K at those companies. Just like
| grinding leetcode can get you in the door, the skills you
| need for advancement are not necessarily the same ones you
| need for making good software.
|
| I hope the parent makes the best of it and becomes good at
| the craft, it will make the job a lot more enjoyable even
| if it may not be the fastest way up the ladder.
| kudokatz wrote:
| > the skills you need for advancement are not necessarily
| the same ones
|
| Exactly this. I suggest learning how to fabricate (or at
| least exaggerate) "impact" to get promoted. It's the
| fastest way to make money once you're in the door. Show
| how much of a team player you are to deliver cross-team,
| impactful results specifically by stepping on bodies to
| get there--it'll make you rich!
| logicslave12 wrote:
| It's been really stressful. I know python, but not really
| any other languages. I'm able to get work done. But I'm
| really nearly the same as a fresh grad. But really, I was
| just bumming around, then studied for four months and
| destroyed their algorithms questions, so much so that
| expectations for me are really high. But all I know is
| leetcode, literally nothing else...
| nnd wrote:
| What was your prep strategy?
| thewarrior wrote:
| Take the same energy and apply it to learning to build
| testable and understandable code. If you can go from
| nothing to smoking an algo interview in months you're a
| fast learner. You'll be fine.
| [deleted]
| TheMblabla wrote:
| I think that's what these leetcode type questions are
| good at. You're either naturally adept enough to do well,
| or internally motivated enough to memorize/learn them.
| Either way, it's a decent signal for a company that needs
| someone to learn their internal, proprietary techstack
| thewarrior wrote:
| I partially agree but this point of view has become very
| polarizing and controversial and I get the other side of
| it too. People who have spent ages getting better at
| their craft feel undervalued. However the two need not be
| mutually exclusive. One needs to learn to do their job
| while also navigating the system. That is part of the job
| just like selling your work is also work.
|
| But having worked at both FANG and non FANG you can see
| the rigor of the interview process reflected in the
| quality of your colleagues. That's something that is hard
| to deny having experienced it.
| kudokatz wrote:
| > You're either naturally adept enough to do well, or ...
|
| I'm personally very wary of using algorithms questions as
| a proxy for how "adept" someone is at _software
| engineering_. If I were running a business, I 'd
| personally want to make sure people could manage
| technical debt and build decoupled systems.
|
| I have had multiple positions at FAANG companies, and
| despite being "adept" according to these algorithms
| questions the systems built by these highly-paid (and,
| around me, generally experienced) people are pretty awful
| in terms of quality and maintenance.
|
| Learning a proprietary stack also hampers effectiveness
| in future positions if wanting to opt-out of FAANG later
| on.
| thewarrior wrote:
| I have observed this problem and usually it's not because
| the people are incapable but that the incentives are to
| ship things that move the needle to quickly get promoted.
| The financial rewards at these companies from promotions
| are huge.
|
| Where the managers have incentivized quality and
| stability my team mates have moved mountains and I've
| seen some really good stuff but otherwise not.
| cik2e wrote:
| Why do you suppose these hires aren't good at learning
| engineering best practices? I see comments like yours
| here all the time. Is it some kind of arrogance, perhaps
| amplified by a false signal sent by getting hired off
| leet code questions in the first place?
| thewarrior wrote:
| It's false based on what I've seen. Plenty of people
| passionate about good engineering where I am. But they
| are sometimes trapped in a system which doesn't always
| incentivize it.
| sieabahlpark wrote:
| You think you're alone?
| mettamage wrote:
| How did you get past the resume screening? Or are you from
| the US, because then it's much easier to get past the
| screeming, or so it seems.
|
| I have yet to be invited for so much as an HR call when it
| comes to FAANG (bachelor/master CS from a Dutch university).
| Maybe I'm not getting past the application tracking system?
| sushshshsh wrote:
| Most likely you either don't have 5 years of professional
| experience or they are filtering you based on
| visa/citizenship status. The industry is very broken.
| vechagup wrote:
| Having a current employee add your resume to an ATS as a
| referral is the most efficient route. Around SF at least
| it's not particularly hard to find someone willing to do
| that even if they hardly know you. This sort of networking
| is likely harder elsewhere, but perhaps not by much.
|
| Simply uploading your resume to a large tech company's
| website will rarely get you anywhere, is what I've heard
| from recruiters.
| jephir wrote:
| Second this. Internal referral is the most reliable way
| to get in the door in my experience.
| mettamage wrote:
| Ah, so that's what I've been doing wrong for 18 months.
| Thanks! I'll be putting this to good use :)
| logicslave12 wrote:
| The recruiter just reached out to my LinkedIn profile. My
| understanding is it's really easy to get the interview
| PragmaticPulp wrote:
| Interviews are only partially about testing your body of
| experience. They're also supposed to test your aptitude and
| ability to grow in the future.
|
| If you were capable of studying Leetcode so hard that you
| mastered the interview process at one of the most selective
| software companies in the world in only a few months, it's
| not much of a stretch to imagine that you could apply that
| same aptitude, ambition, and ability to learn quickly toward
| picking up the basics of git, dev ops, and so on.
|
| Arguably, this is one of the benefits of Leetcode-style
| interviews. They focus on core software engineering aptitude,
| while not arbitrarily excluding people because they didn't
| use the right VCS at their last job.
| [deleted]
| read_if_gay_ wrote:
| > it's not much of a stretch to imagine that you could
| apply that same aptitude, ambition, and ability to learn
| quickly toward picking up the basics of git, dev ops, and
| so on.
|
| But you already have your reward, right? I'm not sure how
| much ambition is left after you actually get the job.
| username90 wrote:
| Promotions can double your salary or more from that level
| so people are plenty motivated.
| lowiqengineer wrote:
| That's definitely not true at companies without incentive
| systems.
| jkcorrea wrote:
| > If you were capable of studying Leetcode so hard that you
| mastered the interview process at one of the most selective
| software companies in the world in only a few months, it's
| not much of a stretch to imagine that you could apply that
| same aptitude, ambition, and ability to learn quickly
| toward picking up the basics of git, dev ops, and so on.
|
| So by that logic, why not just create some game for
| candidates to master. If all you're testing for is "how
| much they want it" and how quickly they pick up on some
| arbitrary system that they'll never use in their actual
| job, then the subject shouldn't matter, right?
| Icathian wrote:
| They already have. And at the time it was being developed
| and gathering momentum, some plausibility as a thin
| defense of it was helpful. Why go through that process
| again now when the existing system is already firmly in
| place?
| zerr wrote:
| Err, but why do you have to prove it for every next job?...
|
| In reality, it's a legal way for:
|
| 1. Ageism - not many seniors are desperate enough or have a
| free time for Competitive Programming preps.
|
| 2. Making switching jobs harder - for every next job one
| has to prepare again, because nobody is using Competitive
| Programming stuff during real work, so you forget.
|
| Keep in mind that CP != CS.
|
| And CP is not everyone's cup of tea. It is a separate
| discipline/subject with its own trivia knowledge & tricks.
| CP uses Computer Science the same way as e.g. Physics or
| Biology use Math.
| PragmaticPulp wrote:
| > why do you have to prove it for every next job
|
| Obviously, each company can't blindly trust the
| interviewing practices of everyone's previous employer.
|
| > Ageism - not many seniors are desperate enough or have
| a free time for Competitive Programming preps.
|
| In my experience, senior developers don't need anywhere
| near as much prep as junior developers for these
| interviews. Leetcode problems are difficult when you're a
| new college grad with zero years of programming
| experience. They're significantly easier after you've
| been programming for 10 years.
|
| > Making switching jobs harder - for every next job one
| has to prepare again
|
| Companies aren't going out of their way to make it harder
| to hire good employees into their own companies.
|
| Leetcode isn't an industry-wide conspiracy. Companies are
| using it because they believe it's a good filtering
| mechanism for candidates. When the Big N companies have
| higher rejection rates than Ivy League universities, they
| can afford to be selective.
|
| > Keep in mind that CP != CS.
|
| The problems are designed to test CS skills.
|
| How else would you suggest reorganizing the interviews to
| test for CS skills?
| jkcorrea wrote:
| #2 doesn't make sense, though: If I'm company B, trying
| to poach from company A, it would be in my best interest
| to make the leap to applying/interviewing less difficult,
| not more for employee's of company A.
|
| Unless you're implying a set of companies are all in
| league with each other to reduce churn/competition for
| talent
| Swizec wrote:
| That's because at FAANG those problems are already solved.
| And there's a team of experts working on each of them. Maybe
| multiple teams.
|
| Your job is to be a clever code monkey. The Process will take
| care of turning your coding into engineering.
|
| Leetcode interviews are great at testing for just that. A
| high IQ willing to solve arbitrary puzzles just because
| someone said "solve this"
| sushshshsh wrote:
| Even at my mid tier company we have processes around the
| crucial but (to me) boring parts of the software industry,
| which involve building, deployment, version control, access
| control, connection drivers, requirements gathering,
| provisioning of resources, maintenance...
|
| The list goes on and on and if someone doesn't do any of
| these things, the whole operation will grind to a halt. And
| absolutely none of these procedures involve reversing a
| linked list or traversing a binary tree inorder (maybe git
| does but that's an implementation detail hidden from me
| ^.^)
| Swizec wrote:
| Correct. And as far as I can tell, devops folks don't do
| leetcode interviews. Most SREs don't either.
|
| At my last interview process (in June) I was being hired
| into a more seasoned role where experience matters more
| than code chops. There was an algorithms question but the
| biggest weight was put on the "Can you design a
| distributed microservice infrastructure with good
| tradeoffs and solid relational modeling"
|
| Series A company so it's conceivable that I'll be
| involved in all parts of the stack.
|
| If I just did well on algorithms (I didn't) and nothing
| else, it would be a hard no hire. But they were very
| impressed when I said "Eh for this load, you don't need
| horizontal scaling except for redundancy"
| username90 wrote:
| But people are taught the basic boring skills required to
| deliver value in a big org in the first few months and
| very few fail to learn them in that time, they are by far
| the easiest skills to teach in software development so it
| doesn't make much sense to test it when hiring.
| jorblumesea wrote:
| Working at the companies that often ask these questions (FB,
| Goog, Amazon, MS, Apple) work at scales that many other
| companies don't. They also develop novel frameworks or work on
| problems that might interest you.
|
| Example: if you want to work for a cloud service provider you
| need to jump through these hoops, even though regurgitating
| Rabin Karp or Tarjan's has little to do with day to day
| engineering.
|
| Another example: Canonical (Ubuntu) Microsoft (windows) and
| Apple (OSX) all ask these questions. If you want to have a part
| in building an OS you will get asked these questions.
|
| Basically if you want to work at "big tech" start grinding and
| don't stop until you move into management.
| non-entity wrote:
| I really wish I could leave the field altogether, but the
| alternatives are things I hate even more or incredibly steep
| paycuts.
| biztos wrote:
| Have you looked into being a software person in a non-
| software (or only "software-enabled") company?
|
| You'd probably get a pay-cut vs. FAANG or whatever, but it
| wouldn't exactly send you tumbling into the working class.
|
| I really enjoyed working on software in biotech, for example,
| where I started my career... and sometimes think about
| returning with all my software-company chops to see if it's
| still as fun!
| non-entity wrote:
| I suppose it might depend on the domain / industry. Biotech
| sounds like it has the potential to be interesting, but I
| currently work for a large non-tech company and have worked
| in government and don't like the being considered the cost
| center or having to deal with the seemingly unending layers
| of bureaucracy.
| biztos wrote:
| In biotech, at least back in the day, bureaucracy
| depended on company size and nationality, and there never
| seemed to be enough hackers for all the random tech stuff
| that needed doing. I'm sure it's changed a whole lot
| since then but as a general point, it was a lot more
| diverse along any vector you like than the software
| world.
|
| Maybe you should find a startup with no layers of
| bureaucracy and no cost centers yet? This being HN, there
| are plenty of them around.
| yodsanklai wrote:
| I spent a lot of time practicing leetcode, interviewed a bunch
| of times (4 times, about 25 technical interviews) at FAANG
| without getting an offer. They always tell me it was very close
| (or even that I passed, but they didn't find a team in the
| following month and asked me to reapply).
|
| What leaves me with a bitter taste is that they don't seem to
| value the experience on my resume (e.g. OSS and tons of github
| projects, blog or scientific articles, things written by me
| they could actually check). It feels like they will favor a
| candidate who can solve leetcode problems a little bit faster
| to someone who is a more experienced SWE. Also the whole thing
| seems pretty random.
|
| Also practicing leetcode feels like wasted time. It's not
| uninteresting but after you solve 500 problems, it starts to
| get uninspiring. There are cooler things to do for personal
| development, especially when you already have a demanding job.
|
| But well, that's part of the game... at least the rules are
| clear, and the interviewers/recruiter are usually pretty nice.
| andreilys wrote:
| " Also practicing leetcode feels like wasted time."
|
| I think take home assignments are worst in terms of wasted
| time. At least your leetcode skills are transferable whereas
| take homes rarely transfer.
| eastbayjake wrote:
| One of the big unspoken reasons these questions stick around:
| they cause little imposter syndrome anxiety for the senior
| engineers who need to conduct the interview. You ask a
| candidate to code a toy problem, and the candidate either knows
| the "trick" to solving it quickly or they don't -- very little
| risk for you as the interviewer, you're just watching things
| play out.
|
| But if your interview requires you to pair program on real code
| like you'll do in your actual job, it opens up a lot of room to
| look dumb in front of an interviewee. You have to handle bugs
| on the fly. You have to look up (for the 5000th time in your
| career) whether you should be using Array.slice or Array.splice
| in this case. You go back and look at a similar implementation
| in your code base for a template instead of coding from memory.
|
| And that's a shame because the live coding exercise is both a
| better predictor of hands-on job success _and_ it 's a better
| recruiting tactic: you've just had a vulnerable, collaborative
| experience with someone who will actually be working with you
| on a regular basis and you get a sense of whether you'd
| actually like to work there. But we keep doing these algorithms
| exercises because they require such little effort or
| interaction from engineers who are doing this interview in
| between two meetings with no prep time.
| biztos wrote:
| I am trying to resist cynicism, but I too am thinking that
| after my upcoming sabbatical if I want to get top dollar I
| should just invest in power-grinding at the leetcode gym.
|
| Still hoping to find a friendly startup though, since some of
| the MegaCorps are lifestyle-incompatible and I'm already used
| to making a lot less than Googlebucks.
| PragmaticPulp wrote:
| > after my upcoming sabbatical if I want to get top dollar I
| should just invest in power-grinding at the leetcode gym
|
| Given that top dollar can mean potentially a six-figure raise
| over median salaries, that doesn't exactly seem like a bad
| deal.
|
| All things considered, Leetcode is remarkably accessible
| relative to the barriers of entry in other high-paying fields
| like law, medicine, certain finance careers, and so on. It's
| a mostly-free website that you can work through at your
| leisure from the comfort of your home, with plenty of Google
| results to walk you through the questions if you run into a
| problem.
|
| Have you spend some time on Leetcode already? I could see how
| the questions could be daunting to new grads, but I didn't
| find it all that painful with several years of industry
| programming experience.
|
| Don't get discouraged by the sheer number of Leetcode
| problems. You don't have to do them all to get value out of
| it. The key is to do a couple per day in your free time
| (lunch break, while you eat breakfast, whatever). Any
| consistent practice will add up over weeks or months.
| biztos wrote:
| Actually I love leetcode (the website) and do it for fun
| once in a while, and if I decide to go for a big grind
| later on then I don't think I'll particularly mind that
| part even if it doesn't get me my ticket to the Google Bus.
|
| The risk of cynicism is that I've been doing this for 25
| years or so and there are some things I'm quite good at
| that can add a lot of value to a company, but it appears
| that the highest-paying outfits will judge me on things
| that are at best _very_ tangentially related to how I can
| make /save them money.
|
| Sorry if my comment came off as anti-leetcode, I have a low
| opinion of the thing so many people use it for, not the
| site itself. Before hearing of my impending sabbatical I
| was even planning to subscribe to the "pro" level and build
| it into my work routine, just as way of differently
| exercising my brain once or twice a week.
| PragmaticPulp wrote:
| > but it appears that the highest-paying outfits will
| judge me on things that are at best very tangentially
| related to how I can make/save them money.
|
| IMO, this is a popular misconception but it's not really
| reflective of reality.
|
| Leetcode is ultra-popular with new college grades and
| people with a few years of experience who want to break
| into Big-N. As such, the vast majority of Leetcode
| discussions online revolve around that demographic.
|
| It's true that the Big-N companies will still be heavy on
| the algorithmic interview questions, but it's not true
| that they'll ignore everything else on your resume. The
| early 20-somethings talking about Leetcode online don't
| have a long resume to point to, so Leetcode is the focus.
| If you show up with a 25-year career of successes, you're
| going to have a very different interview experience.
| username90 wrote:
| > but it appears that the highest-paying outfits will
| judge me on things that are at best very tangentially
| related to how I can make/save them money.
|
| This is very wrong, leetcode is just the baseline and
| don't determine your seniority. Even the best leetcoder
| in the world had to start at the lowest junior level
| after college. Instead they look at your experience and
| what value you can bring to determine if you become
| junior, mid, senior, staff etc, so they very much value
| experience not related to leetcode. However you still
| have to pass the leetcode bar.
| biztos wrote:
| Yes, I will have to pass the leetcode bar, which has very
| little to do with my actual value add. I understand
| that's how it works, I have friends who hire for some of
| these companies, but thanks for explaining.
|
| I strongly dislike having that bar, because I think it is
| irrational to use it as the baseline hoop everyone has to
| jump through. And honestly because it's not my strongest
| suit, I'm sure I'd be less bothered if it was something
| I'm good at and your average fresh CS grad is not. Which
| is kinda how we ended up here I think.
| lowiqengineer wrote:
| How do I maintain flow? I end up extremely depressed and
| disillusioned if I get stuck on a problem - that's really
| what's stopped me from doing consistent prep.
| TeeMassive wrote:
| I'm glad that I am not alone. I've done mostly non-UI
| C++/C#/Java/Python stuff, mostly business level rules and
| devops and evangelizing good practices such as CI and clean
| code and git (you would be surprised how many people don't even
| know how what it is or how to squash and rebase). Having
| studied computer engineering we did not really focus on
| algorithm but more on lower level stuff and signal processing.
|
| I do not really fit any of the "standard" interviews. I've done
| the TripleByte interview and other top 100 corporation
| interviews and they all seem to assume a computer science
| formation or if not than assume you are a web dev. So yeah, I
| know how to implement most algorithms efficiently, I just can't
| remember how to describe exactly Dijkstra's from memory or how
| to balance a tree on a whiteboard under stress. I've seen them,
| I learned them, but 7 years after not using them I forgot (and
| frankly don't care).
| wtracy wrote:
| FWIW, I've found that companies outside the valley,
| particularly those that don't see software as their primary
| product, are more interested in work samples than puzzle
| solutions.
|
| Try broadening your search to things like aerospace and medical
| technology companies.
| non-entity wrote:
| > Try broadening your search to things like aerospace and
| medical technology companies.
|
| Not sure what the correct name is, but most job listings I've
| seen for these industries strongly prefer people with prior
| experience in them because they have to follow strict
| frameworks / processes for safety reasons.
| Hackbraten wrote:
| Why is the title censored?
|
| As a European citizen, I absolutely don't get it. Why can't we
| say fuck on the internet?
| VitalyAnkh wrote:
| Just personal preference. I made this title by myself other
| than censorship. Anyway, "fuck" sounds a little rude.
| TACIXAT wrote:
| This is really cool. What order are the chapters in? Seems
| intense to lead with dynamic programming.
| OnionBlender wrote:
| I got really good at dynamic programming problems but then none
| of the companies I interviewed with asked me a dynamic
| programming problem. These were large tech companies and well
| funded startups. Perhaps it was just luck.
| jorblumesea wrote:
| DP solutions were really in vogue for awhile, and seem to be
| asked less now. I heard a completely unsubstantiated rumor
| that FB found them to cause high false negatives because
| they're such a tricky and specific problem type. Also, once
| you know the "one trick" to solving them they don't help
| illuminate candidate thinking.
| lewapkon wrote:
| Questions with DP solutions are usually not particularly
| great for interviews. They usually don't have any solutions
| in-between brute force and DP. If somebody doesn't come up
| with a DP solution you, as an interviewer, just learned that
| they don't know DP, but it doesn't give you too much useful
| signal on the candidate's skills. DP is just kind of a trick
| that you can learn to solve this specific type of problems,
| but knowing the trick is not something that FAANG companies
| want to test for.
| bradlys wrote:
| Partially luck and maybe you never solved it with a DP
| solution. There are problems for which DP will give an answer
| but it isn't a hard requirement for you to come up with it.
|
| I've received quite a few DP problems in my time
| interviewing.
|
| Then again, I feel like saying I'm unusual. I've received a
| lot of very difficult problems. Almost like the people are
| trying to set me up for failing. ;)
| OnionBlender wrote:
| A good free algorithms book is http://algorithms.wtf (by Jeff
| Erickson)
| unemphysbro wrote:
| I took his class way back in 2010.
|
| Challenging but fun.
| tmpmov wrote:
| Thanks for the write up and git book.
|
| Related question: I'm curious if any has game-ified algorithm
| learning, sort of like those old educational math games targeting
| certain grade levels.
|
| Might be cool to make a point and click adventure centered around
| dynamic programming or greedy algorithms.
| ghj wrote:
| There are plenty of competitive programming sites where you can
| grind rating just like you would for MMR rating in video games.
|
| For example CodeForces, AtCoder, TopCoder, and even LeetCode
| have rated contests
| tmpmov wrote:
| Thanks ghj.
|
| I was aware of top coder/leet code, though hadn't heard of
| code forces/at coder.
|
| For me the adventure game give a bit more concept linkage.
| Take Monkey Island, I can remember how to reply to many of
| the sword fighting insults, or what was needed to get pieces
| of eight via the cannon at the circus. There's something to
| be said for linking problems via a memorable story, giving
| examples and meaning from multiple angles helps retain the
| content over the dryness of problem prompt/quick solve.
| paulcarroty wrote:
| Found in my bookmarks: https://leetfree.com/
|
| Not sure if all quizzes are original, but some of them looks
| interesting.
| fizixer wrote:
| Can anyone explain/interpret what leetfree.com is saying here?
|
| > ... don't try to solve it with online judge ...
|
| > ... Try to learn from the solutions we provided as quickly as
| possible ...
|
| > ... Interviewers only care about your WhiteBoard
| communication skills ...
|
| Are they implying that rote memorization (memorize all problems
| and their solutions) is the best/easiest way to do the
| interviews?
|
| If yes, wouldn't that trip you up the moment you're asked
| something new/original?
|
| If no, what are they saying? Is the best leetcode stuff
| paywalled and they're providing a free version?
|
| what's the latest on step-by-step most effective way to get
| ready for standard coding interviews?
|
| Context: I'm trying to get back into this after many years.
| I've used leetcode in the past but don't remember anything
| about online judge.
| hackermailman wrote:
| Online judge is competitive programming like
| https://open.kattis.com/ or CodeWars or CodeForces meaning a
| server that takes your source, compiles and runs it, tests if
| you satisfied all the req of the challenge. There's books for
| this https://cpbook.net/#CP4content and despite leetfree
| claims of being 'useless because no online judge in
| interview' there is actually 2-3 judges sitting there in the
| interview performing the same function, telling you if your
| code does not satisfy the problem requirements
| OnionBlender wrote:
| Firefox says, "Warning: Potential Security Risk Ahead" for that
| website.
| drenvuk wrote:
| Nice how browsers have trained people to be scared if there's
| not a lock. It's just an expired cert, not revoked, and
| you're not entering payment information.
| MaxBarraclough wrote:
| There's a reason certs have a limited lifetime. People
| _should_ be trained to avoid such websites.
| bohemian99 wrote:
| I haven't seen gitbook before, is this a common tool for
| documentation?
| mettamage wrote:
| Occasionally you see a gitbook on HN. It is mostly for well...
| books and educational content.
| [deleted]
| agentultra wrote:
| I find this little sub-industry building up around, "the coding
| interview," to be highly strange.
|
| Where are the papers that correlate this niche, specialized skill
| to general job performance and productivity?
|
| I get that at certain problem domains the asymptotic complexity
| becomes a baseline for performance so I'm not against testing
| people's knowledge where it's appropriate. But is it really the
| dominating skill?
|
| Reading some of the comments of people who went through the
| pipeline of this cottage industry, it sounds like it's not even
| useful after you get hired. In fact optimizing for it to get
| through the interview sounds like a bad idea! Imagine landing the
| job and having no other skills.
|
| I'm curious how these algo expert/monster/crushing the interview
| businesses survive and perpetuate this highly competitive
| environment.
| hackinthebochs wrote:
| >I find this little sub-industry building up around, "the
| coding interview," to be highly strange.
|
| You should see the sub-industries around passing a board exam.
| Most of us really don't understand the privilege we have
| relative to other high paying professions.
| PragmaticPulp wrote:
| > Where are the papers that correlate this niche, specialized
| skill to general job performance and productivity?
|
| I would love to read this research if it existed in the public
| domain. However, much of this comes down to trade secrets and
| business practices. It's also not very amenable to controlled
| studies.
|
| Practically speaking, these companies have a lot at stake in
| their hiring process. It's strange that so many people are
| convinced that the Big N companies are shooting themselves in
| the foot or otherwise making poor decisions with these
| interview processes.
|
| Leetcode-style interviews might not have supporting research in
| the public domain, but absence of evidence is not evidence of
| absence. That is, just because the research doesn't exist
| doesn't mean that the Leetcode interviews are bad or worse than
| the alternatives.
|
| Even if companies did eliminate Leetcode-style interviews, they
| have to replace it with some other alternative. Most of these
| criticisms fail to suggest actual replacement interview
| processes.
| masterphilo wrote:
| On your last point, the best alternative I've seen is take-
| home projects where it would take less than a week to
| complete. The interviewer is free to frame a problem in a way
| that allows the engineer to apply their real-world experience
| and show their fit for the job. It removes all the variables
| around interview stress/anxiety and as a result is a better
| (but not perfect) indication of their performance.
| PragmaticPulp wrote:
| > On your last point, the best alternative I've seen is
| take-home projects where it would take less than a week to
| complete.
|
| Ironically, take-home interviews are another contentious
| topic on HN and other internet message boards. The common
| complaint is that people don't want to invest much of their
| personal time into interviewing for companies.
| thewarrior wrote:
| Anonymous google employees have claimed in HN comments that
| google has data showing that these interviews do "work"
| whatever that means.
|
| Can any of you post more info here ?
| [deleted]
| Gummaluri wrote:
| Temporary comment for following and future retrieval of this
| post.
| nickx720 wrote:
| This is really sweet. Thank you kind sir.
| [deleted]
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