Oh cool I was working on something similar awhile back and couldn’t find much precedent. The project got retired as our use case went away. But I’d love to revisit it. It’s still on npm as “data-rambler”.

Idea was a DSL that could be loaded into a JS runtime, then fed data streams. Your module would transform that data into various output streams which could then be fed to a separate reporting library. Powering dynamic reports based on a template.

Our first iteration was already pretty powerful but I had some big plans to bring it into a more JS feeling syntax to reduce complexity.