I have started to very slowly collect some of my old code into a shareable library. It is/will become a collection of utility code, wrappers, etc. Some examples of things I will eventually get into the library are wrappers for libicu and compression (mostly gzip and zip). I have no real agenda or goals on what the library becomes (other than useful). I would love some collaborators.
https://github.com/tonywalker1/stuff
Of course, it builds on Debian. However, I use some C++17, so you will need to use Buster or clang from backports for Stretch.
You might also be interested in my Debian build container.
https://github.com/tonywalker1/cpp_dev
I have also thought about moving some of my Ansible code for Debian into a public repo. Is there any interest in helping on a project like that?