What to Expect at Coding Bootcamp if You are Already a Developer | Hacker News Reader

What to Expect at Coding Bootcamp if You are Already a Developer

danielleleong.com

> We do algorithms every day at 9am (9am!) on whiteboards in groups. It’s a pain in the ass, but they’re necessary for job interviews. What’s kind of amazing is that an algorithm that used to take me hours/days last year now takes me 15 minutes.

What does that mean, "do" algorithms, I wonder. Design algorithms based on requirements which describe the inputs and outputs? Implement existing algorithms from a description? Check the correctness of algorithms? Some of all of the above?

If it's the same algorithm as last year, why would it be amazing that it takes 15 minutes to do it (whatever that entails)? If you had to basically reinvent insertion sort the first time and now you can just regurgitate it from memory, of course it's faster.

You are being pedantic. The author obviously meant "algorithms that you might be asked to do on a whiteboard during a tech interview at Google, FB, ect"

I honestly don't know what exactly that means. (Given your nickname, it must be obvious to you, of course).

Is it like, "write down the entire A-star search algorithm in pseudo-code from memory"?

I assumed she meant that they answer questions like "write a function that finds an arbitrary value in a sorted array" and are expected to use a binary search.

I would rather have a programmer look for a library function to do the task, and understand its specification and all its cases, for correct use.

Failing that, I'd expect them to research the solutions online (and offline if necessary). Find some suitably licensed code snippet or failing that, carefully implement it from a quality specification somewhere (an original paper, good textbook or whatever).

The last thing we want is programmers regurgitating from memory what they think are the correct algorithms.

The vanishingly small number of times I've implemented a binary search from scratch over the past several decades, I cribbed it from somewhere. I needed the algorithm not only to find the item but also correctly indicate where a not-found item would be inserted. I don't want to reinvent annoying little crap like that from scratch, only to get some detail wrong, just like whoever did it first, fifty years before me!

Here is a good exercise for an interview. Give someone an obtusely written, confusing specification for an API, together with a task to implement with that API: watch how they defend the code against the corner cases, and deal with the ambiguities. The task would be "make a best effort to solve the task, and write down any questions about the API which block the completion of the task."

Because that's what we deal with: we read docs, try to use things, hit issues, and then research (online, with vendors, source code, etc) to get unblocked.

I might have a part II to the question where some source code of the API is revealed, and the interviewee would have an opportunity to continue. (So they don't walk away with a sense of incompleteness.)

I live in a bubble in San Francisco and post on HN, so when talking to people I usually assume (perhaps incorrectly), that they are all software engineers between the ages of 18-25 currently in the job market, interviewing at all the same hip 5 companies, so I apologize :P .

In software engineer, when applying for jobs at tech companies, you are universally asked to program solutions to algorithms problems on a whiteboard that follow a very specific formula. If you ever interview for a software position, you will get these exact kinds of questions.

Such questions are usually things like:

"Given a N sorted lists of numbers, join the lists into a single sorted list efficiently"

"Implement a Stack which has push, pop, and minimum operations in O(1)"

"Traverse a Tree and print out each item in level by level order" ect

They are all very formulaic and similar. In the last 3 years I've done about 100 algorithms interviews, and 9 out of 10 times it is a question I've been asked before.

You can find other examples at Glassdoor, hacker rank, or project Euler.

http://www.glassdoor.com/Interview/Google-Interview-Question...

https://projecteuler.net/

Did you get hired?

I've received about a dozen job offers in the last 3 years. TBH, I don't even consider myself better than an average programmer. I've just practiced interview questions a lot.

I'd say this only holds for ~70%, although it's likely geographically skewed - I'm in Seattle, you're in SF.

I've interviewed (and been hired, and been successful) at many great companies where we didn't do specific algorithm implementations on a whiteboard during the loop.

I would certainly not throw out a promising candidate because they couldn't remember specifics on a certain algorithm.

You're not alone. I too, have no idea what it means. These things seem to teach a bunch of buzzwords and then maybe lecture about how cool Ruby is for a few days. It is sort of self-taught programmers turned ... not-self-taught.

I happen to really like A-star search. So I'll give this a shot just for fun.

  Let Q[(Node, Cost)] be a priority queue.
  Let G be a graph. (This makes up the search space.)
  Let V be the set of Nodes visited by the algorithm.
  Let S be the starting Node of G.
  Let F be the objective Node of G. (Node we are searching for)
  
  Let D(N1, N2) -> n be a function (computes the number of edges between N1 and N2.
  Let H(N) -> T be a function that computes an admissible heuristic cost for traversing N. (eg, taxicab distance)

  Let Search(G, Q, V, S, F) be a function that finds the lowest-cost path to F:
    Add (S, 0) to Q

    While there are items in Q:
      Pop (N, C) from Q

      If N is equal to F:
        Return the path from N to S. (Trivial parent traversal)
      
      Add N to V

      For each Nc in N's neighbours:
        Set Nc.Parent = N
        If Nc is not in V:
          Add (Nc, H(N) + D(N, Nc)) to Q
    
    Return an error, a path does not exist.

I have to admit this ended up taking longer than I thought it would. ~20 minutes. And I'm not sure if it's correct.

It's really worrying to read that these bootcamps hire instructors who have no experience and whose only relevant education is a different session of the same bootcamp.

This is exactly why I've been hesitant to try them out. Do they have any value beyond credentialing/signaling effects for a comfortably intermediate programmer?

If you're currently working, it's probably not worth the time or money you'd give up to attend. If not, maybe but be very careful about which bootcamp you attend.

It sounds like xiaoma went to a good one (Hack Reactor from her comments) but the author of the article did not. There are no regulatory bodies, so caveat emptor.

At the "bootcamp" where I studied, the primary instructor was a very senior ex-Twitter engineer who had built their internal code class.

Hi fellow HRX!

It was a great investment and a great twelve weeks :)

Fantastic twenty-four for me -- I went the HIR route. Totally worth every moment.

Clearly, your experience was not universal.

People who go to four year schools don't universally have the same experience either. That's the problem with talking about "these bootcamps" or "these universities" or "these" anything.

That's a fair point. But as someone who hasn't been to a bootcamp, I find it impossible to tell the difference between good ones and bad ones, as they aren't accredited or anything like that.

Edit: for tone.

> functions are always referred to as “he”

I've been programming for a while and I'm pretty sure I've never heard someone gender a function

If I write a pure function sometimes I refer to it as a maid...

Likely an Indian instructor. Using "he" is commonly said for "it" in Hindi, because there is no actual word for "it", it's inferred by context.

Not 100% sure. But otherwise, I also have never heard of a gendered program component.

During my physics undergrad, several of my lecturers were German speaking and would refer to algebraic objects as "this guy". e.g. "We take the derivative of this guy and we get blah". Any language which is gendered would probably have this issue when translated to English.

I don't think that's all too uncommon for native English speakers. While pairing, I pretty regularly refer to chunks of code as "this guy" or "that guy".

Maybe they picked it up from someone while learning English and it stuck with them.

This is true, I definitely anthropomorphise my code, but it's usually to abuse it when it doesn't do what I want.

e.g. "What the f'ing hell are you doing, function, you're not supposed to do that!"

Yep.

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