[infamouscow]

This is fine, except when the candidate knows substantially more than the interviewer about how to solve the problem. I was once asked to implement a spsc circular buffer, and I used C++11 atomics rather than a mutex. I wrote up a working solution, but most of the interviewer's followup questions fundamentally didn't map to my wait-free solution. I spent most of the time explaining to the interviewer how atomics and non-blocking algorithms work. The FAANG rejection email came a few days later.

So I don't think these interviews evaluate the candidate's ability to solve complex and abstract problems. They seem to evaluate the candidate's ability to grind contrived sophomore-level computer science homework. Experience solving the real-life version of the problem rather than the academic one is unwanted.

[b20000]

this illustrates the problem very well. your lock free solution is superior yet the interviewer had no clue and you only know about this solution due to experience which is not what leetcode optimizes for.