But I do choose this approach for these problems to not have reusable code on purpose xD I'm not try-harding to rewrite everything for every feature separately, so most of it would be separated and modular, as long as it's required by the initial purpose of the software. However I avoid writing generic and reusable code that only gets rewarded with functional scalability in mind.

And unit testing is honestly not on my list for these kinds of projects. At best I'd write integration tests to challenge the route handlers. But simply using the software is sufficient to cover the predictably unpredictable usage in these cases.