[nightpool]

Yes, I work on an 11 year old Ruby on Rails codebase, and except for a few sections that are a little overengineered and crufty (Asset compilation..... enough said), the bulk of the codebase and the entirety of the "business logic" is really easy to understand and navigate. About the only time new engineers ever have problems finding something is when it's defined in a "has_" macro with dynamic interpolation, but those cases are pretty rare, and you generally learn to recognize them over time. And certainly it makes using and sharing the code much easier when those larger pieces of repetition are extracted (for example, we have an "acts_as_markdown :column_name" macro that defines e.g. column_name_as_html and column_name_as_plain_text methods). And the validation/callback structure makes it really easy to add new features without having to worry about breaking old ones, and the testing experience with rspec is second-to-none.