Facebook senior software engineer interview • Hacker News Board

Re: Facebook senior software engineer interview

#491

Post by Retric » Thu, Jan 07, 2021, 1:36 PM UTC

barnacled wrote: post #480

Retric wrote: post #452

Earlier quoted context omitted.

It really is about interviewing skills. I noticed a strong trend over time that the people I interviewed kept doing better. You need to engage with people without letting things get confrontational. The best advice I can give is look at how entertainers get random audience members to relax and engage in front of huge audiences. Many people lock up in such situations and can barely say their own name, yet with the rig…

You're just making assumptions again. I have witnessed a huge range of anxiety levels from candidates and when you get used to interviewing it is pretty clear what comes down to anxiety and what comes down to simply not being able to program. When a candidate struggles, I gently lead them and help move things along in a very collaborative way - I am also very tolerant of mistakes or poor starts and proactively give e…

Handholding doesn’t solve the problem of someone second guessing themselves, and can make this much much worse. Outside of pair programming it’s normally a solitary activity where people get plenty of time to reflect. Interjecting in the middle of this is again very different from a work environment.

Re: Facebook senior software engineer interview

#492

Post by Retric » Thu, Jan 07, 2021, 1:48 PM UTC

barnacled wrote: post #479

Retric wrote: post #473

Earlier quoted context omitted.

No, I am saying putting someone at ease is only half of it you need to keep them at ease. The standard script I see people use is basically some warmup conversation where everything seems fine, followed by a grilling. Conducting a full interview “without letting things get confrontational” is difficult. However, unless the job actually requires intense face to face confrontation you want to know how well they can do…

No you're assuming that this is what happened because it contradicts your assertion. Your opinion flies in the face of my extensive experience and that of the majority of people, you may want to start considering whether it is you who is mistaken. I don't think a candidate who I put at ease then absolutely hammered would compliment me on putting them at ease would they? Or does your theory stretch to them somehow hav…

When in the face of empirical evidence I adjusted my world view from close to yours to where I am now. Based on your other comment you’ve having people do fuzzbizz, simply split things into two samples and see which they do better with. Interactive face to face help, or an open IDE they can run code on uninterrupted.

If the second group preformed better then presumably the testing methodology played a role with a higher percentage of people being able to actually program than your suggesting.

Granted it takes a lot of interviews to build a reasonable sample, but we aren’t talking about 1% better performance here.

Re: Facebook senior software engineer interview

#493

Post by pseudalopex » Thu, Jan 07, 2021, 1:58 PM UTC

amazoniananon wrote: post #466

gotosleep wrote: post #357

Earlier quoted context omitted.

"if you did get hired for this role and managed to keep it, you'll be a master at this stuff within a couple of years." I wholeheartedly disagree. I have a total of 14 years of experience. I've been at Google for the past 6 years. I'm an L5 (Senior Engineer) and I get good performance reviews. I interview candidates on a fairly regular basis on behalf of Google. I am fully confident that if I had to re-interview for…

> these algorithm quizzes have nothing at all to do with our job There are no algorithm quizzes here, and it's not saying to prep for one. It says you should have a good grasp on these: arrays, heaps, linked lists, searching, etc. And it provides quality references for refreshing that knowledge and for getting practice thinking and speaking about them in human language instead of internal abstract thought. I think we…

CLRS is a literal algorithm textbook. They recommended grinding HackerRank or LeetCode too.

Re: Facebook senior software engineer interview

#494

Post by rglullis » Thu, Jan 07, 2021, 2:10 PM UTC

themacguffinman wrote: post #488

rglullis wrote: post #481

Earlier quoted context omitted.

Though not direct, there should be alignment between what a business creates and offers and consumers' (society's) satisfaction. "Users seem happy", the same can be said about smokers and tobacco. The issue is not even with the smoking per se. If tobacco companies were simply processing the plant and giving users what people have done for hundreds (thousands?) of years, it would be fine by me. The problem of Big Toba…

I have to disagree that they're the same. You're right in saying that "user's seem happy" is not the only metric, but it's quite a stretch to go from "Facebook doesn't optimize for holistic well-being" to "Facebook is as addictive & harmful as Big Tobacco". It's certainly something I believe reasonable people can disagree on and I don't think it's appropriate to shame people for working at Facebook. It's a little off…

You are missing the point. It's not a matter of being "as harmful" as tobacco companies. It's a matter of having a business that thrives by exploiting people's regulatory mechanisms to get them to do something that goes against their self-interest and well-being.

They don't have to be "the cause of all modern problems" to be frowned upon. Just the fact that they are part of the problem and not part of the solution is enough for me to want to get rid of it and to think poorly of anyone that wants to work there.

Re: Facebook senior software engineer interview

#495

Post by sershe » Thu, Jan 07, 2021, 2:36 PM UTC

driverdan wrote: post #395

Hydraulix989 wrote: post #387

Earlier quoted context omitted.

I'm an athlete-turned-software engineer at FAANG. This is the NFL scouting combine: 40-yard dash, Bench press (225 lb repetitions), Vertical jump, Broad jump, 20-yard shuttle, 3 cone drill, 60-yard shuttle, Position-specific drills, Interviews – each team is allowed 60 interviews in 15-minute intervals, Physical measurements, Injury evaluation, Drug screen, The Cybex test, The Wonderlic test I would consider this set…

Other than Wonderlic everything you listed is directly related to athletic ability and are things athletes do on a regular basis. You're supporting my point. I'm saying testing should be directly related to the position. If someone doesn't need to do binary math or write complex sorting algos from scratch you don't test those, just like how you wouldn't ask an athlete the mundane questions I posted above. You might a…

So what would you do instead? Being able to write some code on a simpler problem vs real-life code is an equivalent of a 40 yard dash vs rushing for a touchdown (or whatever). Being able to find special cases, or design, or figure out a simple algorithmic puzzle is the equivalent of the same for larger problems. The alternative is letting the candidate talk about their projects or to have some hand-wavy design exercise, something too easy to BS.

Re: Facebook senior software engineer interview

#496

Post by barnacled » Thu, Jan 07, 2021, 3:13 PM UTC

Retric wrote: post #492

barnacled wrote: post #479

Earlier quoted context omitted.

No you're assuming that this is what happened because it contradicts your assertion. Your opinion flies in the face of my extensive experience and that of the majority of people, you may want to start considering whether it is you who is mistaken. I don't think a candidate who I put at ease then absolutely hammered would compliment me on putting them at ease would they? Or does your theory stretch to them somehow hav…

When in the face of empirical evidence I adjusted my world view from close to yours to where I am now. Based on your other comment you’ve having people do fuzzbizz, simply split things into two samples and see which they do better with. Interactive face to face help, or an open IDE they can run code on uninterrupted. If the second group preformed better then presumably the testing methodology played a role with a hig…

>Interactive face to face help, or an open IDE they can run code on uninterrupted.

I've tried both. I've tried leaving them to it entirely, I've tried leaving them to it then if they get stuck helping both from a lesser to a greater degree.

It really makes no difference - the bad coders struggle on that and other problems, they just lack the ability to think through the problem.

And again I've seen enough anxious candidates to see the difference. I'm pretty good at gauging things well as to how and when to help.

Overall I'm not hearing many specifics more 'I am great at interviewing'.

The empirical evidence is overwhelmingly that there are many bad programmers out there with long CVs. That's also my experience WITHIN companies, though a lesser proportion.

Re: Facebook senior software engineer interview

#497

Post by driverdan » Thu, Jan 07, 2021, 3:19 PM UTC

spoonjim wrote: post #401

driverdan wrote: post #395

Earlier quoted context omitted.

Other than Wonderlic everything you listed is directly related to athletic ability and are things athletes do on a regular basis. You're supporting my point. I'm saying testing should be directly related to the position. If someone doesn't need to do binary math or write complex sorting algos from scratch you don't test those, just like how you wouldn't ask an athlete the mundane questions I posted above. You might a…

But the engineers at FB do need to be able to write sorting algorithms from scratch rather than just have knowledge of sorting. The reason is that the engineers have to be reasonably fungible so that they can be easily moved between projects as projects are started and stopped. So they could easily be tomorrow thrown into an environment where a sorting algorithm is needed, they are the ones responsible (so they'll ne…

FB has thousands of employees who write code. I highly doubt many of them are writing sorting algos from scratch. They should know which sorting solves the problem and use an appropriate library.

The same applies to most other low level problems. They should understand the problem and the best practice to solve it. In most cases writing low level solutions from scratch is not the best practice.

FB is a mature company now with a slowed growth rate. They've been dealing with scale and performance for long enough now that it shouldn't be necessary to write all of these things from scratch.

Re: Facebook senior software engineer interview

#498

Post by Retric » Thu, Jan 07, 2021, 3:23 PM UTC

barnacled wrote: post #496

Retric wrote: post #492

Earlier quoted context omitted.

When in the face of empirical evidence I adjusted my world view from close to yours to where I am now. Based on your other comment you’ve having people do fuzzbizz, simply split things into two samples and see which they do better with. Interactive face to face help, or an open IDE they can run code on uninterrupted. If the second group preformed better then presumably the testing methodology played a role with a hig…

>Interactive face to face help, or an open IDE they can run code on uninterrupted. I've tried both. I've tried leaving them to it entirely, I've tried leaving them to it then if they get stuck helping both from a lesser to a greater degree. It really makes no difference - the bad coders struggle on that and other problems, they just lack the ability to think through the problem. And again I've seen enough anxious can…

Fair enough, I can accept it could be a difference in candidate pools or something. That said, I personally saw a bump from about 40% to 90% using different methods for what it’s worth.

In terms of a test I use mean, median, mode, and range for an array. Then go into basic performance trade offs.

Re: Facebook senior software engineer interview

#499

Post by clusterhacks » Thu, Jan 07, 2021, 3:56 PM UTC

driverdan wrote: post #398

paxys wrote: post #249

Earlier quoted context omitted.

I have been a tech interviewer for a decade, and this is spot on. The entire reason FizzBuzz-style questions are popular in screening interviews is that most people fail them.

I imagine this problem is much worse at large, highly paid, highly desirable companies. My experience in hiring at smaller companies has not shown this. I've never had a candidate with 10+ years of experience who couldn't code.

We are a smaller org and hire occasionally for roles that are most suitable for early career applicants.

We always get several applicants with 10-20 years of experience who have programming projects on their resume or described in their cover letters.

But in our (very minimal) technical evaluations, lots of these candidates can't do anything at all. No coding, psueudo-code, nothing.

Usually, it turns out they have been really doing light IT work for years - using reporting tools, maintaining little scripts, even just some Excel jockeying. But they still think of themselves as software engineers.

My gut feeling is that lots of these candidates could learn (relearn?) to code, but have spent years not coding.

I don't have the numbers in front of me, but I would guess that the majority of these types of candidates (10-20 years of experience) that apply to our roles can't code in an interview situation and haven't been programming recently.

It is definitely not all of the experienced candidates who fit that profile. The few very experienced candidates we get who can code are often excellent but are looking for salaries well beyond our range.

Re: Facebook senior software engineer interview

#500

Post by cutemonster » Thu, Jan 07, 2021, 4:26 PM UTC

binarytox1n wrote: post #467

cutemonster wrote: post #432

Earlier quoted context omitted.

How do they react when they fail Fizzbuzz?

I make a judgement call - either I end the interview immediately or skip most of the rest of the interview, let them think they made it all the way through the interview and say that we will get back to them with a decision later. When I end it immediately they usually take it badly but these are times that I just can’t justify wasting any more time on them. The bad reactions run the normal gamut of bad human reactio…

That's interesting:

> [I] let them think they made it all the way through the interview

Maybe then, although they get rejected later, they still won't be particularly upset at your company -- since the in person interaction was friendly and positive (i suppose), and you can take some time and write a friendly rejection email or phone call too (i suppose you have a template)