Writing backend for indie game. Scoreboard, events, chat, pain

In 2016, Anton started writing a single-player browser game based on Travian and Heroes in JS. Five years and 30K SLOC later, he decided to add common events for all players. And so it went: the announcement system, the table of records, the events themselves, the distribution of rewards. Everything was done in a simple way, on Flask. Then the chat provider "tightened the screws" and before the release of the beta had to write his own chat. 
On the day of release, 31.12.2021, Anton found out how bad the idea was :)