I have built web service to be able to track dota2 pro matches on live and watch recent matches:
The repo is closed, but I can tell you that it was developed on latest version of aiohttp. This python framework is the best option for me to write small and big projects with async I\O operations. For storing data I use MongoDB. Front part is made with vuejs.
The most challenging part in this project is to collect all useful data is one place, but official web API has some fields in distributed API endpoints.
Now it is in current development, but I think it's stable :)