[mden]

> Why invent "safety" practices and ignore every documented software engineering best practice?

That seems unnecessarily brutal (and untrue).

> 2,000 line long modules and 200-line methods with 3-4 if-levels are considered harmful

Sometimes, not always. Limiting file size arbitrarily is not "best practice". There are times where keeping the context in one place lowers the cognitive complexity in understanding the logic. If these functions are logically tightly related splitting them out into multiple files will likely make things worse. 2000 lines (a lot of white space and comments) isn't crazy at all for a complicated piece of business logic.

> Comments that say what the code does instead of specifying why are similarly not useful and likely to go out of date with the actual code.

I don't think this is a clear cut best practice either. A comment that explains that you set var a to parameter b is useless, but it can have utility if the "what" adds more context, which seems to be the case in this file from skimming it. There's code and there's business logic and comments can act as translation between the two without necessarily being the why.

> Gratuitous use of `nil`

Welcome to golang. `nil` for error values is standard.