CEL is becoming a "standard" implementation found in a lot of places. I generally like it, but loathe how much it's been growing the Yaml Engineering (devops) space. We need better options like CUE and Starlark that can scale and CEL feels more like duct tape in a lot of places. You kind of need CEL-in-config when the values are dynamic and processed within another system. In time, I expect that if something like GitHub Actions supported CUE natively, we could remove the `when: "CEL expression"` even with the dynamic values from previous steps. Eventually CUE's evaluator will be smart enough to know when / how to order sub-values.

- https://cel.dev

- https://github.com/google/cel-spec