My scene is hobby operating system development, where you build an operating system usually for x86 / x86-64 PCs from scratch booting either from the BIOS, or UEFI, and then going from there. Common languages to use are C, C++ or (recently and my personal favourite) Rust.

Personally I'm currently working on an AHCI storage driver (i.e, for talking to SATA drives) for my operating system.

There's a lot of information out there, especially at https://wiki.osdev.org/ about how to get code booting, and about lots of the basic hardware works. There's also places like https://www.reddit.com/r/osdev/ for asking people for help.