I posted last week about a PM tool that I'm building (https://getartemis.app) and I got lots of great feedback.
Particularly, one user wanted a backend API for PM related tasks that one could hook into with other products and let them integrate together. For example, you could make a widget showing how the build process is going for a certain task by integrating with your CI tool. Or you could generate task reports and other types of reports through the API automation, ie if X then route info to Y and auto export as PDF, then email to Z, monthly/quarterly/yearly. You could even build your own kanban front end because I'd take care of all the backend such as with task and epics management.
I'd go so far as to say it's somewhat like Segment or Zapier but more focused on project management and automation. Is this something anyone would be interested in here?