I really like these &quot;how do other people do X?&quot; questions on HN. Thanks for asking it!<p>I work at a small startup with a roughly 10-person eng team.<p>When we write docs we focus mainly on architecture and processes. The architecture docs often emerge from a &quot;tech spec&quot; that was written for the development of a feature that required a new service, or substantial changes to a new one.  We keep everything in Github, in a README or other markdown files.<p>We also write API docs for HTTP endpoints. These are written with client developers and their concerns in mind. When doing this for a Rails app we use rspec_API_documentation, which is nice, but it can be annoying to have testing and documentation so tightly couples. We&#x27;ve talked about changing how we do this, but we always have more pressing things to do.<p>We never write docs for classes or modules within an app&#x2F;service.