- The projects here seem to be short, well-defined and decent way to familiarize with internals of a few technologies (such as Redis, Docker etc.)
- This repo also seems to be good: https://github.com/codecrafters-io/build-your-own-x.
For e.g., write and OS in Rust- complicated and likely not useful for me.
- https://github.com/jepsen-io/maelstrom#documentation - uses Ruby though.