Comment by FranksTV | Hacker News Reader

Comment by FranksTV | Hacker News Reader

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I got a job as a front end developer. We had a ton of streaming data and needed to index it in the front end.

The "right" solution would be to fix it in the back end so that we didn't fetch all that data when it wasn't needed, but that wasn't possible because of the horrific project/product management.

So I had to build binary search trees to index the data so we could work with it fast enough to have a reasonable user experience.

So yeah -- you will need some of this stuff. You're constantly going to be searching for things, reversing things, looking for patterns.

it won't be so clear and abstract, as a leetcode puzzle but the reason why I had to write that binary tree was because whoever came before had clearly never considered using one and was doing everything completely wrong. It was a disaster and made the codebase insane.

If they filtered in the hiring process for people who know the basics then things would have been a lot more performant, and they wouldn't have burned so much time working around the performance issues caused by his terrible solution.

I absolutely agree that hiring folks who are aware of the basics is important -- essentially, you want engineers who are aware of the space of possibilities.

In my view, what makes folks dislike typical coding interviews is that in the real world, what you need is a solid understanding of what algorithms exist and when to use them/what to look for, rather than the knowledge of how to build one on-the-fly.

To solve the issue you described, you don't need to know offhand how to implement a binary search tree on a whiteboard. You do need to know how to identify indexing as a bottleneck, and how to broadly think about a solution. You could then search for indexing strategies and, having studied them at some point in the past, you'd be able to pretty quickly refresh your memory and find the one that's a good fit for the problem at hand.

For this reason, I've always thought these exercises would be much better off as essentially "open book" rather than real-time whiteboarding problems -- because that reflects how engineers actually work. That's also what I've pushed for in my own workplaces, and we've had good success finding talented folks, and heard positive feedback about this aspect of the process.

I would add to this that while knowledge of computer science algorithms and data structures is _absolutely_ useful, being able to implement a binary search tree RIGHT NOW, in under an hour, is not necessary for... pretty much any job anywhere.

Interesting, thanks for that.

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