Any interviewer who designed a question with those kinds of pitfalls in it has done a bad job. This question is good partly because the memcached codebase is it

Any interviewer who designed a question with those kinds of pitfalls in it has done a bad job. This question is good partly because the memcached codebase is itself good. It’s not so abstract that the candidate needs to chew through a whole class hierarchy or plugin system in order to make changes, and yet it is complicated enough that the will have to make important choices, particularly with how to handle a new type of operation.