Hi everyone,
We are big fans of the Deployments timeline and its underlying Deployment API provided by Jira Software Cloud:

There are many resources and examples provided by Atlassian here: https://support.atlassian.com/jira-cloud-administration/docs/integrate-your-deployments-with-jira/
We have successfully integrated this api with our Jenkins server that is used for build and continuous integration of our apps: https://support.atlassian.com/jira-cloud-administration/docs/integrate-jenkins-with-jira/
It works really well to give a "ticket centric" view over the past deployments that is especially adapted to CI/CD pipelines.
I think that this topic deserves a dedicated discussion to exchange best practices and real life feedbacks/questions that arise when you start integrating various deployment tools (ex: GitHub, GitLab, Bitbucket, Jenkins,...).
We are quite experienced with Jenkins integration and we will be happy to share this experience with the community.
We would also love to get feedback from other "deployment api" users ! ;-)