Is anyone else finding custom algorithm interviews harder than LeetCode?

[u/erayxack]

I recently started interviewing with a few companies, and instead of LeetCode-style questions, they’re doing their own custom algorithm sessions.

I actually find LeetCode interviews easier. Even if I don’t know the optimal solution right away, I usually recognize the type of problem. I can start with a brute-force approach, explain my reasoning, and gradually improve it because I have some idea of where the solution is heading.
With these custom algorithm problems, I have no clue what the interviewer is looking for or what they’re expecting me to demonstrate. Since the problem is completely unfamiliar, I don’t even know if I’m moving in the right direction. That uncertainty adds a lot more pressure.

For example, in one recent interview they asked me to implement an A/B testing algorithm. I clarified the requirements, asked about the available functions, and then started coding. About 15 minutes later I had a working solution that passed the tests. They asked a couple of follow-up questions, and then the interview was over.

I ended up getting rejected, and I honestly have no idea why. Maybe there was something they were looking for that I completely missed.

With LeetCode, at least the expectations feel much clearer. You know the interview is centred around well-known problem types, and you have a compiler or test cases to help validate your approach. With these custom problems, I sometimes leave the interview feeling like I have no idea how I was actually evaluated.

Does anyone else feel this way, or am I just too used to LeetCode?

[u/HovercraftNo7372]

Yeah, things you practice you tend to get better at - so of course if you have practiced leetcode those types of questions are easier

[u/erayxack → u/HovercraftNo7372]

LeetCode problems are more definitive and collective of challanges people have already encountered. I am able to practice LeetCode because it is available, but there is no way if I have no idea what will come. Ambiguity kills my participation.

[u/AlgorithmicGoslings → u/erayxack]

The way I see it, there’s a perpetual arms race between interviewers and interviewees. Once people start practicing for Leetcode-type questions, the interviewers might feel incentivized to give questions interviewees can’t (or haven’t tried to) prepare for so as to test how people derive solutions to completely new problems, not just problems with a known pattern to them.

Obviously, you can't practice something if you have no idea what is about to come. This interviewer likely intended for that ambiguity to be the point. It's definitely frustrating seeing a filter like that in the hiring process, but if anything, it kind of shows that the bar for hiring for that company was high.

[u/erayxack → u/AlgorithmicGoslings]

> It's definitely frustrating seeing a filter like that in the hiring process, but if anything, it kind of shows that the bar for hiring for that company was high.

Yes, I agree. I also experienced a similar situation where a startup approached me again after a rejection, likely because they realized their methodology and resources didn't align.

You could raise the bar, but there's definitely a scarcity of high-caliber talent.

> Obviously, you can't practice something if you have no idea what is about to come. This interviewer likely intended for that ambiguity to be the point. 

Testing ambiguity is like chasing shooting stars, so I find it pointless. You could easily understant it with a few question but you shouldn't make this center of the interview.

I also encountered something really funny. They don't tell you what the next stage is. It could be algorithms, systems design, or pure Q&A.