For context, Forge is Atlassian's product extensibility framework that lets you write your own plugins (for lack of a better word) for our cloud SaaS products: https://developer.atlassian.com/platform/forge/

Coming up in a few weeks from another of my teams will be a feature we call "Dynamic Pipelines" which will let you use a similar Forge lambda function to mutate/generate Bitbucket Pipelines workflows at runtime.