So, what do you need? What can I build for you? I'm looking to build something like a SaaS, maybe an API.. What are some of your pain points? My target are probably other developers, or students, or other teachers, people that I can relate to..
* self compiling compiler (self-hosting?).
* self interpreter interpreter (metacircular evaluator)
[from scratch. no parser generator or backends like LLVM, or tools like that, as they hide much info and insight]
Testing
* Fuzzer (for testing, e.g. programming language implementation)