Ask someone? If you have ever been part of a founding dev team you know there is gonna be stuff in the code that is unpleasant to untangle unless you are acquainted with how/why it was done. If you have some kinda searchable chat/FAQ thing I am sure someone has encountered this before or will in the future. I always thought slack was pretty good at storing years of dev questions threads in a single channel due to its informal question/answer nature vs something like stack overflow or Confluence