Tynker - Game Worlds for Kids to Learn Programming
HackerRank - HackerRank is a platform that allows companies to conduct interviews remotely to hire developers and for technical assessment purposes.
CodeCombat - Learn programming with a multiplayer live coding strategy game.
AlgoExpert.io - A better way to prep for tech interviews
StackHive - Design, develop or publish websites right from your browser
Codility - Codility provides a SaaS platform with advanced validation, security and protection features to evaluate the skills of software engineers.