Interesting, I've been enjoying https://www.codeeval.com/ https://www.codeeval.com/ which also has the headhunter based model and supports a few more languages,

Interesting, I've been enjoying https://www.codeeval.com/ https://www.codeeval.com/ which also has the headhunter based model and supports a few more languages, but doesn't have the time limits like a real code interview usually would.