In Perl there is a framework called Mojolicious that has an OpenAPI plugin that does not use a code generator. I find it extremely elegant as it uses annotation

In Perl there is a framework called Mojolicious that has an OpenAPI plugin that does not use a code generator. I find it extremely elegant as it uses annotations in the spec to route the endpoints to the desired controller method. We often need several dialects of our API, and now we can just deploy the same code, but with an altered spec. Very little overhead.