[gauravk95]

A 40-minute algorithmic riddle, may give you a gist of what the candidate is capable. But, you never know for sure, if he/she will perform well in actual work environment.

You have to understand what your technical challenges are and what you are hiring for..? Do you need a generalist or specialist? Does you product require a lot of new algorithm?

I have seen candidates that are extremely good at algorithmic puzzle, but lack the overall approach to build stuff, candidates that have a lot of projects and not so good at algorithmic riddle excel. Also seen the pretenders that show they have done a lot of projects and domain expertise, but when you dig in, you come to know that those project where either trival or they where just lucky to be a part of a team good team.

You will have to be very careful on getting candidates that actually are interested in building things and not just for the sake of interview and a job the prepare for the algorithmic riddle...but you never know for sure, until he/she start working on the project.