I interviewed at six top companies in Silicon Valley in six days • Hacker News Board

Re: I interviewed at six top companies in Silicon Valley in six days

#601

Post by rimliu » Sat, Jan 19, 2019, 9:29 AM UTC

molodec wrote: post #470

rossdavidh wrote: post #291

When I was a new college grad, I felt trapped by the fact that everywhere I looked they wanted several years of experience, and I had none yet. How can I get experience if it's required to get the job? Now that I am 51, I feel annoyed that all of these stories of interviews involve asking questions about algorithms that rarely come up in real coding, and if they do you should NOT be rolling your own code, you should…

I wrote a custom HashMap for Java, used BFS and DBS on graphs, wrote a top down custom parser, custom string searching algorithms to solve real business problems. I would rather work with someone who knows how neural networks really work rather than who knows pytorch or keras, because they can be learned rather easily. In some industries knowledge of algorithms can be more valuable than knowing a myriad of frameworks…

There are people who really know how NN work? I thought there were only people who know how to implement them ;)

Re: I interviewed at six top companies in Silicon Valley in six days

#602

Post by collyw » Sat, Jan 19, 2019, 9:31 AM UTC

rossdavidh wrote: post #291

When I was a new college grad, I felt trapped by the fact that everywhere I looked they wanted several years of experience, and I had none yet. How can I get experience if it's required to get the job? Now that I am 51, I feel annoyed that all of these stories of interviews involve asking questions about algorithms that rarely come up in real coding, and if they do you should NOT be rolling your own code, you should…

I feel exactly the same.

Re: I interviewed at six top companies in Silicon Valley in six days

#603

Post by creato » Sat, Jan 19, 2019, 9:31 AM UTC

odorousrex wrote: post #80

guessmyname wrote: post #9

> If it’s of any use: I was interviewing for my second job out of college with about two and a half years of experience without any particularly notable internships or employers on my resume; I went to a very small school that had zero known software companies at their “career fair”; I started preparing in late April and started applying in June/July; and, lastly, a few months in, my job is everything I could have po…

I cannot help but think that these big tech companies (FAANG, et. al) are missing out on diversifying and increasing their engineering expertise by passing over developers like you. I often think what would Google/Facebook would be like if they hired in some experienced engineers that may not be able to whiteboard a BFS tree or can tell you Djikstra's algorithm, but have proven business track records of getting proje…

> I often think what would Google/Facebook would be like if they hired in some experienced engineers that may not be able to whiteboard a BFS tree or can tell you Djikstra's algorithm

I think this happens less than people think. I've been at two big tech companies and interviewed people while at both (and obviously was interviewed myself).

I think what trips people up is that many questions have solutions that are given by "named" CS algorithms like the ones you listed, but also have simpler solutions that are fine too. And honestly, candidates that invoke named algorithms and (maybe eventually regurgitate the textbook algorithm) are often not the good ones (to me at least). Most problems like this often have simplifications that good candidates take advantage of to do something custom (and much simpler) than the "named" algorithms.

Basically, if I'm interviewing you and you regurgitate a famous algorithm... well I'm not going to ding you if you do it correctly, but in my experience, I'm much more likely to give a good review to someone that methodically works out a simple solution instead. Often the people that successfully dig up a named algorithm and apply it can't talk about it very well.

So, I suspect that a lot of the people that complain about not knowing a famous algorithm in an interview simply failed to work out a simpler solution to a simpler problem and didn't realize it.

Re: I interviewed at six top companies in Silicon Valley in six days

#604

Post by Drdrdrq » Sat, Jan 19, 2019, 9:36 AM UTC

turtlecloud wrote: post #494

acpetrov wrote: post #321

Earlier quoted context omitted.

I just graduated, so I'm not dealing with constant internship interviews anymore, but at the time I absolutely hated it. My frustration isn't exactly like yours (my time is probably a lot less valuable). I feel that the questions are all geared at puzzle solvers. If you're a puzzle solver, you love answers. You love digging into the details. You love finding out the basic components of a system. I think these are the…

I agree with you. The puzzle solver ABSOLUTELY hate it if you somehow say that the question is flawed. Ie if you think outside the box and render their hypothetical situation flawed. It’s as if they didn’t spend enough time to realize that they are missing the forest for the trees.

To be fair, almost everyone hates it when you show them they are wrong. Especially in the setting where they are supposed to be judging you, remember? And even in normal settings it pays to think about how some critique will be received by the other side. It's a slippery slope in the interview... For me it would raise red flags if the flaw was pointed out in an inappropriate manner. After all, this is the person who would be involved in code reviews where sensitivity to other people's feelings (and egos) is very important.

Re: I interviewed at six top companies in Silicon Valley in six days

#605

Post by saagarjha » Sat, Jan 19, 2019, 9:44 AM UTC

laumars wrote: post #597

saagarjha wrote: post #382

Earlier quoted context omitted.

It’s the same reason high school students apply to Stanford and MIT; there are amazing programs everywhere but top-level universities carry prestige and may have higher quality opportunities.

I did cover those points. As I said, the prestige is misguided (in the case of FAANG) and you don't need to go down the FAANG route to have access to higher quality opportunities. Those companies sure want you to believe what you're claiming because it means they get the first bite of the cherry but the reality is very different (from my experience anyway).

You can have higher quality opportunities everywhere; it’s just that it’s often easier at those companies. Just like going to certain universities means it’s easier to find professors who lead their field, recruiters from better companies, and more access to be with smart people.

Re: I interviewed at six top companies in Silicon Valley in six days

#606

Post by kstenerud » Sat, Jan 19, 2019, 9:48 AM UTC

One big problem is that the people interviewing are rarely "big picture" people, because in general there are few "big picture" people as a percentage of any population.

So, when "small picture" people think "competence", they think in minutiae, which in software development means the smallest distinct units: algorithms.

I've been in the industry long enough to see it everywhere, and it's not necessarily a bad thing. Most people prefer tactics to strategy, and you only actually want a small percentage to be strategists anyway; too many chiefs and whatnot.

But when it comes to the technical interview, it's frustrating to deal with a tactically minded rather than a strategically minded person.

Re: I interviewed at six top companies in Silicon Valley in six days

#607

Post by GuB-42 » Sat, Jan 19, 2019, 9:51 AM UTC

rossdavidh wrote: post #291

When I was a new college grad, I felt trapped by the fact that everywhere I looked they wanted several years of experience, and I had none yet. How can I get experience if it's required to get the job? Now that I am 51, I feel annoyed that all of these stories of interviews involve asking questions about algorithms that rarely come up in real coding, and if they do you should NOT be rolling your own code, you should…

Even if if you don't roll your own code, knowing how it works is still important. I see cargos cult code far too often.

Granted that you only need a vague idea about the algorithm. But going from a vague idea to working code is also a valuable skill.

Re: I interviewed at six top companies in Silicon Valley in six days

#608

Post by laumars » Sat, Jan 19, 2019, 9:56 AM UTC

saagarjha wrote: post #605

laumars wrote: post #597

Earlier quoted context omitted.

I did cover those points. As I said, the prestige is misguided (in the case of FAANG) and you don't need to go down the FAANG route to have access to higher quality opportunities. Those companies sure want you to believe what you're claiming because it means they get the first bite of the cherry but the reality is very different (from my experience anyway).

You can have higher quality opportunities everywhere; it’s just that it’s often easier at those companies. Just like going to certain universities means it’s easier to find professors who lead their field, recruiters from better companies, and more access to be with smart people.

But is it actually any easier given you have to also factor in going through their painful recruitment process and actually getting employed by them in the first place?

Maybe my things are different in London than they are in SV but I've never had any issues. Quite the opposite in fact; I've been turning awesome jobs down.

Re: I interviewed at six top companies in Silicon Valley in six days

#609

Post by brabel » Sat, Jan 19, 2019, 10:02 AM UTC

jammygit wrote: post #348

lowdest wrote: post #319

Earlier quoted context omitted.

As I see it, the difficult algorithm interviews screen for people who are motivated enough to spend 100s of hours studying for an interview, or know this stuff for some other uncommon reason. Both types are acceptable hires.

Wouldn't it be better to hire somebody who thought that was lame and who spent 100s of hours learning performance testing, new libraries, design patterns, or just working on projects? Personally, I'd rather not work somewhere that hired based on drilling fringe information - what will the job be like? Maybe I'll feel differently in 10 or 20 years

> Wouldn't it be better to hire somebody who thought that was lame and who spent 100s of hours learning performance testing, new libraries, design patterns, or just working on projects?

I would hope so, because I do all those things and, after over a decade writing software, find the ability to solve puzzles almost completely useless for most coding I've ever done. But reality doesn't need to make sense. So, if you want to work for Google or Facebook, learn puzzles anyway :)

Re: I interviewed at six top companies in Silicon Valley in six days

#610

Post by Xeronate » Sat, Jan 19, 2019, 10:04 AM UTC

jedberg wrote: post #571

Xeronate wrote: post #379

Earlier quoted context omitted.

I can tell you really don't know what you're talking about because you can't just "use libraries to do it". You can use a library to parse a given input, but you need to traverse the tree in a specific way. Here, I'll give you an example of the first step of the problem with proprietary info stripped out. https://gist.github.com/tohsa/2d906942f8712abdfc7df72128479c... You plain and simple need to know BFS to do these…

Ok I see where the problem is. I read through your code and didn't think "BFS", I just thought "knows how to nest for and while loops". I suppose you could consider this "knowing BFS", but I would consider this table stakes. I would never ask about something like this in an interview. I thought you were talking about actually using BFS on a data structure, in which case I'd use a library to do it so I don't have to r…

I agree with you that my gist demonstrates "table stakes", but I think that is the level of tree traversing most interview questions require. I don't think any interviewers are asking people to implement distributed algorithms like the one you linked. They are asking for algorithms that just combine a few of the basics. With that said, I'm inclined to believe our fellow commenters are arguing about the utility of what I shared. For example people siding with me gave examples of finding the biggest file in a file system and constructing a dependency graph to refute the idea that tree traversal are useless and mentioned that there isn't any "deep understanding" in BFS because it's so simple. It reminds me of the tweet by the creator of Homebrew[0] about not being able to reverse a binary tree that so many people bring up when this topic arises. To me that's just table stakes.

On the topic of my example not constituting "knowing BFS", the BFS I shared is just a slight modification of what most students are taught and is close to the second method for level order traversal of a tree on geeks for geeks[1]. If you don't like the BFS usage because it isn't on an explicit tree (although nested HTML templates most definitely form a tree), the result of parsing an AspxFile in my gist returns an explicit tree data structure[2][3] and the helper method[4] at the bottom does a standard preorder traversal[5] on that linked structure. That feels like "actually using DFS on a data structure".

[0] https://twitter.com/mxcl/status/608682016205344768?ref_src=t...

[1] https://www.geeksforgeeks.org/level-order-tree-traversal/

[2] https://gist.github.com/tohsa/2d906942f8712abdfc7df72128479c...

[3] https://github.com/PositiveTechnologies/AspxParser/blob/mast... (AspxParseResult has a reference to the root AspxNode, and btw I didn't write this parsing library)

[4]https://gist.github.com/tohsa/2d906942f8712abdfc7df72128479c...

[5] https://www.geeksforgeeks.org/dfs-traversal-of-a-tree-using-...