[shoulder-track]

The problem here is that for lots of big projects, there are typically only so many people who really drive the project to the completion. If you work for a big bank, you'd actually have a couple of people like you and a dozen of bystanders who lend a hand here or there, but are barely competent. They will have exactly the same resume as you, and it might even look more impressive. But their 20 years of experience in development is really just a couple of years played over 10 times.

So when hiring, I don't care if you're slow and methodical, or super fast. What I care about is that you understand basic algorithms and data structure (lists, sets, maps, trees) and can apply them to simple problems without me telling you that using a hash map here will speed up the solution tremendously, or using a heap will simplify the code. Those simple problems are also taken from most common patterns we see in our codebase, which consists of lots of geospatial data processing and analysis.

And if you need more than an hour to solve a couple of those simple problems (let's say, find duplicates between two lists), you'll definitely have a problem fitting in with the rest of the team - since everyone on the team has solved those problems and agrees that we need people with at least this basic algorithm knowledge to be able to make a significant contribution here.

These questions also a first hour of the interview, the rest goes deeply into discussion of previous projects you made, different architectural patterns, etc.

[dominicjj]

>And if you need more than an hour to solve a couple of those simple problems (let's say, find duplicates between two lists), you'll definitely have a problem fitting in with the rest of the team

result = set(l1) - set(l2)

Time taken: 20 seconds. I take your point that you need people with at least a certain level of competence. I found I saved those who were hiring an awful lot of time by sending them example code or asking them to give me a challenging weekend project as a test, perhaps even something they needed doing for real. But I dread these exam-like online tests where I have to have a right answer in 20 minutes. I don't work like that. Few people over 40 do any more.

[recursive]

If you're talking about python, I believe you - where you should have &.

And there are many developer position applicants that wouldn't be able to do it. If you actually solve it in 20 seconds, I presume you passed the test.

[dominicjj]

Oops - set intersection not difference.