www.codewars.com is a website for daily programming challenges. Each challege typically takes 10-45 minutes to complete. The challenges are ranged on a scale of 4 "dan" to 1 "dan" with 4 "dan" being the hardest problem and 1 "dan" being the least hard. This scale is reseved for the problems at the "Master" level. Codewars also has 4 other categories that use an additional tag as described below:

Proficient:

1 kyu

2 kyu

Competent:

3 kyu

4 kyu

Novice:

5 kyu

6 kyu

Beginner:

7 kyu

8 kyu

For more information on codewars please visit: https://www.codewars.com/about