This was quite fun but I do find the UI with multiple overlapping windows a bit confusing and difficult to navigate, particularly when you click on a type definition and open another file. Does anyone know what UI library it's using? I'd prefer to see a list of the files and then be able to go into each one individually, as it is there is a lot more clicking with the mouse than I'd expect with a CLI.
Great advice here on making code readable - it's definitely easier to decode what someone is thinking if the happy path is always on the left, and errors are dealt with and returned. Most go code I've seen adopts this style.