Split and synchronize Minecraft server (server)?

I'm currently trying to solve the problem with the lagging of the server with a number of players over 50 in the 1.12.2-1.17. My idea was that I would connect several small servers with bungeecord, doing things like e.g. Inventory data can be saved in a DB when entering and exiting the server or having all .yml .config files as one file in the cloud, e.g. Google Drive. The Google Drive variant would force me to use a Windows server, which I don't really like (habit).

I build the system for a survival server, which is why a cloud system like cloudnet is not an option.

Do you have any ideas how to synchronize individual files or how to solve the above problem?

It doesn't look like Microsoft wants to solve the problem…

Thank you in advance, if I have not explained something clearly, I'm sorry, I'm a native German speaker

A MySQL database? Or did I get your question wrong?

Yes and no I want the same server to be split up I have already written part of the necessary system (everything that happens live) which regulates the chat etc. I also wanted to do that with the db, but maybe there's a ready-made system that makes it easier so that I don't have to change every pl that is not db compatible. In addition, many functions are not available, as separate sub-servers are usually simply created.

At least I don't know of any such system.