I'm a front end developer, so NestJS was a blessing for helping me write my API. It gave me a set of rules to follow and amazing utilities to make my life easier, such as exception filters [0]. One thing I admittedly struggle with is knowing when to create a new Nest Module versus a new service in an already existing module, and I do not think Nest provides such guidance on application architecture. However, I believe this is a result of my minimal back end experience, and shouldn't be held against the NestJS project. Overall, I am really enjoying it.
[0] https://docs.nestjs.com/exception-filters