I started programming a few years ago, and I've always wanted to make a social media. Although I am still not too advanced, I managed to put together one for my own (and maybe others) happiness.
I decided to use Flask (Python) for this. I implemented a JSON based mappings "database" and a directory of all the music pieces (I'm still trying to figure out proper databases), and made the Flask script manipulate it. On the frontend, I wrote nice little Bootstrap (HTML) pages, with just simple forms. For music notation and playing, I used html-midi-player. Music is organized under users. It's all MIDI based, and music uploads must be MIDI - but you can use your favorite editor for it! Everything is like a stateless API - it's super simple.
I called this platform "Sailnote" (Sailboat - note, get it? Sorry about the bad joke; but its the best name I could come up with). Also, note that this is not a social media - its essentially a glorified file sharing platform.
It's open source too, and maybe contribute (there may be bugs, but probably no big ones)! It's on Codeberg: https://codeberg.org/splot-dev/sailnote
Here's the link to my hosted version: https://snote.pythonanywhere.com/
Thanks for reading this!
