Earlier quoted context omitted.
I tried writing a simple crud api with asp.net, which should parse and respond json. It was the worst development experience I ever had while writing json apis. Validation? Not existent. OpenAPI/swagger documentation generation? Not existent. Then it also tried to force me into using MVC, while acting that it is express with its middlewares. I switched back to node.js with fastify and wrote my app in an hour. I reall…
FluentValidation and Swashbuckle are two great libraries for the tasks you referenced. This is a good enough reference repository should your curiosity be piqued again in the future: https://github.com/jasontaylordev/CleanArchitecture
Failing to find the differences between them will impede learning in general.