* https://codewars.com
* https://codingame.com
* https://hackerrank.com
* https://codefights.com
* freecodecamp.org
* https://www.sololearn.com/
* https://www.frontendmentor.io
* https://learndigital.withgoogle.com/activate/courses
* https://codesignal.com/
thanks!!!