Ask HN: Small/medium sized C++ (& Rust) programs that are designed well?

Hello all,

Curious if anyone has any good examples of well designed systems projects. I am looking mainly for C++ but Rust projects would be good as well.

Often when I ask this type of question, people show repos that are very large and it takes a lot of effort to figure out what is going on before then needing to understand the design. I was hoping people could point to some smaller projects, even just personal ones.

Thanks!