I made specs for every part of the code in a separate folder and that had in it logs on every feature I worked on. It was an API server in python with many services like accounts, notifications, subscriptions etc.
It got to the point where managing context became extremely challenging. Claude would not be able to determine business logic properly and it can get complex. e.g. if you want to do a simple RBAC system with an account and profile with a junction table for roles joining an account with profile. In the end what kind of worked was I had to give it UML diagrams of the relationship with examples to make it understand and behave better.