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Ask HN: Can engineers from Google or Facebook solve whiteboard questions easily?

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Re: Ask HN: Can engineers from Google or Facebook solve whiteboard questions easily?

#201
post #101

Earlier quoted context omitted.

I also work at Google and what mystifies me when I do interviews is just how consistently people manage to screw up even the medium difficulty questions. I used to love asking this question until it was banned: https://programmingpraxis.com/2012/01/20/knights-on-a-keypad... This is a great question because it has several levels of solutions: 1. A recursive solution that iterates over all sequences, exponential time a…

How would you rate this solution? Assuming we have static keypad grid. long moves(int start = 1, int len) { assert(len > 0); long[] cur = new long[10]; for (int i = 0; i 0) { nxt[0] = cur[4] + cur[6]; nxt[1] = cur[8] + cur[6]; nxt[2] = cur[7] + cur[9]; nxt[3] = cur[4] + cur[8]; nxt[4] = cur[3] + cur[9] + cur[0]; nxt[5] = 0; nxt[6] = cur[1] + cur[7] + cur[0]; nxt[7] = cur[2] + cur[6]; nxt[8] = cur[1] + cur[3]; nxt[9]…

Very good! However there is an off-by-one error as the exercise asks for paths of lengths not number of nodes. If you came up with that in 45 minutes without googling, you are very strong indeed.

Re: Ask HN: Can engineers from Google or Facebook solve whiteboard questions easily?

#202
post #199

Earlier quoted context omitted.

I'd have to "just walk away" from the entire industry, since I've never once in over twenty years had an interview which did not involve a demonstration of my ability to reason through a problem and communicate a proposed solution using conversation and a whiteboard. I am a professional, yes, and thinking about problems and communicating about solutions is my job ; why should I be offended that someone wants me to sh…

That's nice in theory. But it doesn't fit the facts. 1) The whiteboard questions are unrelated to the job opening. The interviewers have no idea why you are there. They don't know what your resume says. They don't know who you might be working for. They don't know what you might be working on. Would you hire someone to work for you without knowing if they were going to clean your house, install new lighting, or rebui…

Your theory does not fit my facts, and I can't relate to your "clown-nose" metaphor. I respect the fact that you've been working in the industry almost twice as long as I have; but if the environment you describe were as universal as you are making it out to be, I would expect to have encountered it by now (and I have interviewed at both Google and Facebook, as per the original question, along with plenty of others).

With regard to your point #1, it's not that the questions themselves must necessarily be related to the specific job one is interviewing for; it is that the process of communicating about problems and collaborating in the investigation of potential solutions represents the core of the profession. I have no idea what you mean by "no known relation" in point #3; there certainly are niches in which someone capable of nothing more than writing code might be able to eke out a living, but for the most part software engineering consists of interpreting user needs and definitions of problems, investigating those problems sufficiently to derive specifics, designing solutions which make appropriately balanced trade-offs, and communicating plans and progress in order to ensure that the proposed solutions satisfy customer needs. Sure, there's also a little typing of code every now and then, but if that's all someone brings to the table their potential contribution is very limited.

I am not aware of any studies which provide any meaningful data about software interviewing practices; we are all guessing. I would take the complaints about the use of whiteboards and toy problems in technical interviews more seriously if the people making such arguments were able to present a superior alternative, but the proposals I've heard sound even more like your "clown-nose" concept than the system we're used to.

Re: Ask HN: Can engineers from Google or Facebook solve whiteboard questions easily?

#203
post #199

Earlier quoted context omitted.

That's nice in theory. But it doesn't fit the facts. 1) The whiteboard questions are unrelated to the job opening. The interviewers have no idea why you are there. They don't know what your resume says. They don't know who you might be working for. They don't know what you might be working on. Would you hire someone to work for you without knowing if they were going to clean your house, install new lighting, or rebui…

Your theory does not fit my facts, and I can't relate to your "clown-nose" metaphor. I respect the fact that you've been working in the industry almost twice as long as I have; but if the environment you describe were as universal as you are making it out to be, I would expect to have encountered it by now (and I have interviewed at both Google and Facebook, as per the original question, along with plenty of others).…

The environment I describe is not universal, nor did I claim it was. In fact, I am advocating walking away from the subset of companies that do whiteboard interviews.

About your reply for point #1, I agree that communication and collaboration are important. I have picked up chalk (I'm old) during an interview in order to draw diagrams related to robot paths. But you'll note that I decided that the chalk-talk was an effective way to communicate essentially visual information. A "whiteboard" interview is one where the interviewer decides that I need to use a whiteboard to communicate. Coding is not a whiteboard activity and the medium choice is inappropriate. I rarely choose to communicate algorithms with an interpretive dance for that very reason.

About your reply to point #3, in any large company it is highly unlikely that a single, new-hire person would have such a broad scope of activity. Hiring a person of that scope would cause me to invest in background checks and presentations by the person showing their prior projects, designs, and outcomes. I certainly would learn nothing by asking them to reverse a tree on a whiteboard in 20 minutes.

As to your final point, I did present a superior alternative. Have the hiring manager talk to the person about the job opening and the skills expected. Ask the person to provide related background information from their prior experience. Ask them about how they might appoach a current or previous problem related to the job opening. If THEY want to use the chalkboard to communicate that's fine.

An interview tells you a lot about a company and how it treats employees. If you see a "sea of desks" in a supermarket-sized open-plan floor you can assume you're "just another ball in the ball-pit". If they hold meetings in a fisherman's net strung from the ceiling (I wish I made that up, but no...) then you can assume they have a playground mentality. If they are proud of their "80 hour weeks" you can assume your pay rate is only half what it claims. If "free food" is given as the best reason to work there, you can assume the work is painful and boring. And, to the original point, if the interview process resembles a frat-house hazing-style "paddle line" of unrelated interviews, you can assume a frat-house "good culture fit" mentality. Every frat house strives for a monoculture (as in, "we only hire the best and the brightest").

But if you're a professional, working every day to improve your skills and breadth of knowledge and experience, then respect yourself. Walk away.

Re: Ask HN: Can engineers from Google or Facebook solve whiteboard questions easily?

#204
post #199

Earlier quoted context omitted.

That's nice in theory. But it doesn't fit the facts. 1) The whiteboard questions are unrelated to the job opening. The interviewers have no idea why you are there. They don't know what your resume says. They don't know who you might be working for. They don't know what you might be working on. Would you hire someone to work for you without knowing if they were going to clean your house, install new lighting, or rebui…

Your theory does not fit my facts, and I can't relate to your "clown-nose" metaphor. I respect the fact that you've been working in the industry almost twice as long as I have; but if the environment you describe were as universal as you are making it out to be, I would expect to have encountered it by now (and I have interviewed at both Google and Facebook, as per the original question, along with plenty of others).…

Just to add facts to my argument, here is a posting from today's Hacker News about how to prepare for a Javascript interview: https://github.com/IamManchanda/algorithms-javascript

Walk away.

Re: Ask HN: Can engineers from Google or Facebook solve whiteboard questions easily?

#205
post #71

I am a SWE at Google, and yes, most Googlers are pretty good at solving whiteboard problems. It's not like we are born with those solutions in our heads, but we enjoy solving those questions especially with other people. It's a lot of fun to "explore" answers to these questions, and that's what I think interviews are all about. I know HN hates whiteboard problems, but just like anything, you get good with it if you'r…

We don't hate whiteboard problems because they aren't fun. They're obviously fun for some people. We hate them for interviews because they're a terrible signal for hiring, they're often poorly administered, they're humiliating, they discriminate against introverts, and they've become frustratingly common. They unfairly mess with people's livelihoods. It is a really big, life-altering issue for some people.

Yet, with such a terrible signalling tool for engineers billion dollar companies like Facebook, Google, Microsoft, Uber with complex technical challenges were able to manage. /s

Re: Ask HN: Can engineers from Google or Facebook solve whiteboard questions easily?

#206
post #75

I worked for FB. I like the whiteboard problems and many other engineers like them too, and I enjoyed discussing or solving similar problems over lunch. That's probably why they're so prevalent in interviews -- I don't believe they actually predict a candidate's success in a company. Btw in college, I used to compete on websites like topcoder, spoj, etc for fun. The interview processes of many companies drastically f…

And there are people who just find these stuff boring/mundane and also don't think it is worth to allocate months for preps. There are lots of other great opportunities so why bother?
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