HackerRank

HackerRank is a technology company that offers competitive programming services where computer programmers compete by writing programs according to provided specifications. HackerRank's programming challenges can be solved in multiple programming languages, and these challenges are sorted into different computer science fields.

Programmers ares automatically scored and ranked globally based on their performance in these challenges. In addition to individual coding challenges, HackerRank also hosts contests where users compete on the same programming challenges during a set period of time and are then ranked at the conclusion of the event. These challenges are a form of gamification. The consumer side of their website is free for coders to use.