[gafferongames]

Generally I've provided this as a homework task, with the ability to email me and ask specific questions to help guide the candidate over a period of whatever time the candidate wants.

There are definitely degrees of correctness and completeness and depending on the candidate experience and level, certain solutions are acceptable. For example, a totally naive implementation in golang that doesn't quite hit the scalability requirements would be a good conversation starter and would pass a mid level or junior candidate.

A senior or above "badass" candidate would be expected to hit the scalability requirements.

An incredible candidate would teach us something new about this problem that we don't already know.