I personally note all the code I use in multiple ways, even if I'm the only owner. General design and architecture especially helps in over-modularized environm

I personally note all the code I use in multiple ways, even if I'm the only owner. General design and architecture especially helps in over-modularized environments. I think I had a similar modularized nightmare at my last job where each file was split into 3 files too many. Taking notes on how they connect and even drawing our the graphs can help a lot. Depending on how it would be received by your coworkers (sounds like not very well), you could make a main design doc in each repo and maybe sub documents in separate namespaces.