C - Design your own free( ) function

Question

Today, I appeared for an interview and the interviewer asked me this,

1. Tell me the steps how will you design your own f

Answer 1

There is an architecture that malloc and free are supposed to adhere to -- essentially a class architecture permitting different strategies to coexist. Then the version of free that is executed corresponds to the version of malloc used.

However, I'm not sure how often this architecture is observed.