Postgres and MySQL/mariadb are all primarily written in C.
Contrary to what other posters here claim, most programming languages are not written in C, but are self hosted. Ie. written using themselves. This usually involves a small bootstrapping component written in C or something similar, but that is a minor part of a whole
That we stop fawning over tech CEOs
Thank you for saying this. Sometimes I feel like I sm the only one thinking like this 🙇♥️
Pet peeve: don't use string keys. It invites key collision errors. Use the fact Go supports structs as keys in maps. Safer and more efficient.
You should probably change page content entirely, server sizey, based on the user agent og request IP.
Using CSS to change layout based on the request has long since been "fixed" by smart crawlers. Even hacks that use JS to show/hide content is mostly handled by crawlers.
Depending on your needs you can also break it into a columnar format with some standard compression on top. This allows you to search individual fields without looking at the rest.
It also compress exceptionally well, and "rare" fields will be null in most records, so run length encoding will compress them to near zero
See fx parquet