Recruting process has changed: now almost all hiring and recruiting companies require candidate to make online task excercise.

Using modern web technology it’s poosible now to write code, compile and execute directly in the browser.

And Microsoft released Visual Studio Online.

There were released many platform for online testing. You can see their review in this article: The Top Technical Screening Platforms in 2019.

The same platforms can be used not only by hiring company but also by programmers to improve their technical skills and prepare for this kind of tasks.

See 15 Sites for Programming Exercises.

And here is my list:

1. coderbyte
2. hackerrank
3. codility
4. codesignal
5. coderpad
6. qualified
7. codingame
8. leetcode
9. GeeksforGeeks
10. codechef
11. DevSkiller

After completing these tasks I started to add my code in this Github library. Everybody is free to use it.