hackattic - No nonsense, real world programming challenges
Codewars - Achieve code mastery through challenge.
Frontloops - Level up your frontend skills with handcrafted tasks
Real Dev - Real-life coding skill challenge
HackerRank - HackerRank is a platform that allows companies to conduct interviews remotely to hire developers and for technical assessment purposes.
devpad.io - Devpad.io helps conduct the coding interview