Everyone contest writer writes "thanks to MikeMirzayanov for great Codeforces and Polygon platforms" in the contest announcement blog. At the onset it might look like MikeMirzayanov runs a tight ship and people have to kiss his ass to continue writing contests! But as one spends more time on the platform, they will start appreciating the differencing factors of Codeforces.
Though I don't know much about Polygon, I wanted to thank MikeMirzayanov for Codeforces platform and thought I'll take some time to write why. In my opinion, here are the key things which makes Codeforces platform exceptional.
Ability to filter all the successful submissions for a problem (during and outside of contest) and ability to sort it by 'execution time' or 'submission time'. Sorting it by execution time helps analyze optimization techniques and sorting it by submission time helps to see what are the approach of quick solvers.
Ability to access contest details and tutorials from the contest dashboard page and from the problem to which the contest belongs. This is a blessing while solving the problem to quickly access its editorials. Some times the contest preparers does not use this functionality e.g. http://codeforces.com/contest/704. So we have to rely on Google search to get to the tutorials :(.
The standings page is awesome! I can quickly access all the solutions from all coders (especially top coders). IT ALSO SHOWS SUBMISSIONS OUTSIDE OF CONTEST!!! How cool is that!
Ability to add favorite coders as friends and track their solutions during the contest and outside of it. I generally like to filter solution of certain coders. So
friends standingspage helps to do just that.
Ability to filter problem set by tags helps to target specific type of problems to solve.
Problem statistics on the contest dashboard page and problemset page gives a good idea on the complexity of the problem.
Ability to hack during the contest. The hacker gets the points and the hacked can know the issue in their solution before the contest ends and has a chance to fix it and resubmit. Everybody wins!
Simple text based pages. There are not many fancy buttons, images and animations on the web page. Considering the coding platforms are for technical developers and not for general (non technical) users, it makes sense not to burden it with flashy content and animations.
Last but not the least, the good set of contest writers and testers. I have not seen many instances where the problem statement is not clear or substandard solutions pass due to weak tests. I should say at this point the problem statement can be bit lengthy than required most of the times. Especially when you want the Div 2 problem A out of your way and you see full page statement you go REALLY!
So, thanks MikeMirzayanov and your team for great Codeforces platform.
If you like any feature that I missed, please leave a comment.
Edit: The statement that begins with "At the onset" is a badly written joke. When I read it now, it sounds like a serious statement!
Edit 2: New additions
Ability to send messages to users.
Ability to set favorite contests, problems and submissions. I recently discovered that I can set favorite on a submission. This is awesome! If I like an implementation, I can track it permanently.