There is some rate limiting for the OAuth 2.0 JWT Bearer token authorization grant flow.
In May 2017, D. Meyer wrote that rate limits don’t apply to Jira Cloud REST API calls performed under the add-on’s identity. The situation may have changed since then, so I kept looking.
The Atlassian REST API policy includes this interesting statement:
“Resource and rate limits, and the default and maximum sizes of paged data ARE NOT considered part of the API and may change (possibly dynamically). It is the responsibility of the client to read the road signs and obey the speed limit.”
Road signs. Wut?