[johnamata]

Course? Like with lectures and work? The only one I know that does it is the premium course at https://watchandcode.com/ where the premium's focus is teaching students how to read (javascript) codebases. They start you with a small library then you graduate to exploring increasingly complex open source codebases, along the way picking up concepts in computer science and javascript. It has a heavy focus on contributing to open source, advanced students are working on open source projects such as those from Mozilla. It uses javascript though, so if that's not your cup of tea, then your best bet are blog posts and books, such as

- xv6: https://pdos.csail.mit.edu/6.S081/2021/xv6/book-riscv-rev2.p...

- tensorflow (google translate can do PDFs): https://github.com/horance-liu/tensorflow-internals