Real Dev - Real-life coding skill challenge
Xobin - Most Comprehesive Pre-Employment skills testing and Psychometric Assessment Platform.
hackattic - No nonsense, real world programming challenges
After Interview - Get feedback from job interviews to improve
HackerRank - HackerRank is a platform that allows companies to conduct interviews remotely to hire developers and for technical assessment purposes.
Interviews on Skype - Test candidates using a real-time code editor over Skype