failed ➡ 422 - Unauthorized ➡ 401 - Forbidden (know who you are, but you can't do it) ➡ 403 - Not found ➡ 404 - Duplicate ➡ 409 - Something else you depend on failed ➡ 424 - Rate limiting ➡ 429 - Timeout ➡ 408 - Too many stuff on body ➡ 413 - Didn't implement that method ➡ 405 - and so on… Avoid 400