Depends rather on the project. So, in my current role (Go) I generate part of the code for new APIs that I am implementing, from OpenAPI specs. I just write th

Depends rather on the project. So, in my current role (Go) I generate part of the code for new APIs that I am implementing, from OpenAPI specs. I just write those JSON specs manually in my IDE - The JetBrains tools (not sure if it's a plugin?) have a real-time preview you can have up side by side, which is good enough, with the openapi standard open on the other monitor. While in an old role we had a legacy (Java) system which was a bit of a pain for others to integrate with, so we did the reverse - With a little bit of work we had an endpoint serving up a Swagger UI with autogenerated API docs (based on our comments/annotations) for people to read, for all those old existing APIs.