Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Google Tech Dev Guide

techdevguide.withgoogle.com

Post reply on HN
Print view View original

41–50 of 250 posts

Re: Google Tech Dev Guide

#41

Post by lwansbrough »

ascar wrote: post #38
lwansbrough wrote: post #2

"Given a string S and a set of words D, find the longest word in D that is a subsequence of S." Found under "Foundations of programming" -- this is exactly the type of problem I'd expect as question one under this section. When it's made by Googlers, that is. I make a lot of cool stuff day to day, and usually that requires a lot of code and knowledge about programming and topics that are rather advanced (currently I'…

I agree with you that a non significant number of developers need this kind of problem-solving ability for their daily work, but I would disagree that they never need it. And when they do it can have huge impact. There are many applications of these fundamental problems in system building. They are usually not as obviously in your face as the coding interviews and it is often not possible to let a library do that stu…

My thought process: 1.) this is an intersection problem, 2.) what does a quick search have to say about efficiently solving an intersection problem in $language? That thought process does not require any algorithm knowledge. That knowledge is already out there in abundance, and there are enough people smarter than me focused on those problems that I am wasting everyone’s time by implementing a solution myself. (Btw the answer in C# is LINQ, if you wrote an algorithm yourself I’d call you a bonehead and tell you to rewrite it. I suspect the answer is similar for any other language that has a standard library.)

Re: Google Tech Dev Guide

#42

Post by macspoofing »

lwansbrough wrote: post #28
macspoofing wrote: post #20

Earlier quoted context omitted.

>currently I'm building a distributed collaboration system with event sourced data in Microsoft Orleans I know it's easy and fun to use frameworks that abstract all the gory low-level details (the equivalent of calling a built-in sort function on a list of numbers), but somebody has to write those frameworks at some point. Don't get me wrong, I'm certainly impressed with the work that the Orleans team did and it woul…

That's precisely my point. There's a handful of guys at Microsoft building this awesome framework. Anyone else interacting with it needs to understand some details of the framework but it's mostly abstracted away from them. And those developers can be exceptionally well suited to their jobs without understanding the underlying algorithms that make Orleans work. Calling the algorithm design "foundational" is like sayi…

I think my issue is an attitude that celebrates ignorance.

>Calling the algorithm design "foundational" is like saying it's foundational to understand how an intake manifold is designed in order to build a car.

Here's a big picture view, the most talented developers I know have a very good mental model of low level details, and also tend to be pretty good at algorithmic questions. I don't think that's a coincidence.

I know that day-to-day programming tends to consist of solving rudimentary problems and worrying more about high-level code organization and architecture rather than micro-optimizations of some function. But it has also been my experience, that even in those cases there will be times when you will run into a problem that will require you to put together an algorithmic solution with a data structure you learned way back in uni that is analogous to the kinds of puzzles you disparage.

As a challenge, why don't you try to do one of those puzzles per day for a month - I guarantee you will find value there.

Re: Google Tech Dev Guide

#43

Post by AzzieElbab »

m0zg wrote: post #36
akanet wrote: post #5

Earlier quoted context omitted.

That's certainly your opinion, but the subsequence problem is a very general, abstract question that offers the candidate a number of ways to arrive a progressively better solution by following their intuitions. It's not the greatest interview question, but it's certainly not the worst. This website appears to be for people who already know how to code, and offers many different paths as well.

It doesn't. This seems like a typical Google interview question. If you didn't know how to solve it before the interview started, you aren't going to figure out anything other than a brute force solution in 45 minutes. And brute force solution will not get you a good grade in a tech interview at Google. It's idiotic: once you do get hired by Google, easily 80% of your work is copying one proto buffer into another, an…

oh no. are you saying google tech interviews are basically trivia

Re: Google Tech Dev Guide

#44

Post by mav3rick »

lwansbrough wrote: post #41
ascar wrote: post #38

Earlier quoted context omitted.

I agree with you that a non significant number of developers need this kind of problem-solving ability for their daily work, but I would disagree that they never need it. And when they do it can have huge impact. There are many applications of these fundamental problems in system building. They are usually not as obviously in your face as the coding interviews and it is often not possible to let a library do that stu…

My thought process: 1.) this is an intersection problem, 2.) what does a quick search have to say about efficiently solving an intersection problem in $language? That thought process does not require any algorithm knowledge. That knowledge is already out there in abundance, and there are enough people smarter than me focused on those problems that I am wasting everyone’s time by implementing a solution myself. (Btw t…

And what if you don't have a standard library ? You're working on a new device, on a new language ?. Frameworks breed programmers with less adaptability, foundations breed problem solvers that can adapt across problems.

Re: Google Tech Dev Guide

#46

Post by mav3rick »

komali2 wrote: post #35
steve_musk wrote: post #21

Earlier quoted context omitted.

The point isn’t to build something new, but to learn CS foundations. Being able to think through this type of problem is absolutely worthwhile.

Why is it worthwhile? Given finite time, a person could instead learn how to use a new established framework, API, or even programming language.

Because APIs and languages change every few years. Concepts and foundations don't. If I move to a company using a new language, I am good enough to pick it up because the design of my sofware is more about the data structures and their interactions.

Re: Google Tech Dev Guide

#47

Post by ascar »

lwansbrough wrote: post #41
ascar wrote: post #38

Earlier quoted context omitted.

I agree with you that a non significant number of developers need this kind of problem-solving ability for their daily work, but I would disagree that they never need it. And when they do it can have huge impact. There are many applications of these fundamental problems in system building. They are usually not as obviously in your face as the coding interviews and it is often not possible to let a library do that stu…

My thought process: 1.) this is an intersection problem, 2.) what does a quick search have to say about efficiently solving an intersection problem in $language? That thought process does not require any algorithm knowledge. That knowledge is already out there in abundance, and there are enough people smarter than me focused on those problems that I am wasting everyone’s time by implementing a solution myself. (Btw t…

You have two lists of objects and the thing you want to compare against is a property nested two levels deep in one kind of object and one level deep in the other object. Are you sure you still want to pass this to a library and not write this simple and basic approach yourself?

1. Pick shorter list

2. Create hashmap comparable -> object

3. Iterate longer list and check for each item: comparable in hashmap?

Done.

That doesn't need a library. Sure, let's say in Java, you could maybe pass your custom implementation of comparable to the library, but is this seriously your interpretation of better code? In fact in many cases the library can't help you, because your structures are not as basic as the library would need them and transforming is a huge and unnecessary overhead.

That's the thing, you usually don't need (and want) to implement an algorithm on basic strings. But the kind of problem, where you need the same approach but don't have strings appear a lot. Especially if you enjoy to work in system infrastructure like I do.

Re: Google Tech Dev Guide

#48

Post by gowld »

lwansbrough wrote: post #24
MikeLui wrote: post #17

Earlier quoted context omitted.

What would you consider foundational?

Algorithms aren't foundational, in my opinion. Once you understand the syntax of programming, you can start learning about the applications of that syntax, which for 99% of developers rarely ends up in the shape of an explicit algorithm. It's not all bad, debugging is foundational for sure. I'd place a person's debugging skills, their ability to predict bugs, system design, knowledge of common (applicable) libraries…

You seem to have a nonstandard definition of "foundation". It doesn't mean "introductory" or "beginner"; it means "what everything else is built upon".

Re: Google Tech Dev Guide

#49

Post by SamReidHughes »

m0zg wrote: post #36
akanet wrote: post #5

Earlier quoted context omitted.

That's certainly your opinion, but the subsequence problem is a very general, abstract question that offers the candidate a number of ways to arrive a progressively better solution by following their intuitions. It's not the greatest interview question, but it's certainly not the worst. This website appears to be for people who already know how to code, and offers many different paths as well.

It doesn't. This seems like a typical Google interview question. If you didn't know how to solve it before the interview started, you aren't going to figure out anything other than a brute force solution in 45 minutes. And brute force solution will not get you a good grade in a tech interview at Google. It's idiotic: once you do get hired by Google, easily 80% of your work is copying one proto buffer into another, an…

> If you didn't know how to solve it before the interview started, you aren't going to figure out anything other than a brute force solution in 45 minutes.

I'd never heard this problem before and it took a few seconds to think of something better than brute force. Many colleagues I've worked with would too, and could probably improve on their first non-brute-force idea over the span of 25 minutes.

Re: Google Tech Dev Guide

#50

Post by m0zg »

snaky wrote: post #40
m0zg wrote: post #36

Earlier quoted context omitted.

It doesn't. This seems like a typical Google interview question. If you didn't know how to solve it before the interview started, you aren't going to figure out anything other than a brute force solution in 45 minutes. And brute force solution will not get you a good grade in a tech interview at Google. It's idiotic: once you do get hired by Google, easily 80% of your work is copying one proto buffer into another, an…

> figuring out how things work in the absence of documentation That would be great interview test actually. Given a bunch of unknown code, add some simple functions, not breaking it apart. Keeping the style (not only syntactically) would be a bonus.

Yes, I actually implemented such a thing at a company I worked at after Google. We'd give the candidate a fairly simple and self contained codebase, and ask them to add a simple, incremental feature in the span of an hour. No limits on legitimate internet access, stack overflow, etc, and using their favorite text editor (we had several already set up). This worked great for us, as it selects for people who can solve practical problems in code they're not familiar with, which is bulk of the work of any software engineer.
Post reply on HN