I love Starlark. I was a major implementor of it at VGS (the repo is open: https://github.com/verygoodsecurity/starlarky). It had unique distinct features that made it much easier to control and sandbox than many other languages out there.

I even built a codemod library that does a very basic python -> starlark so that one can develop using python ecosystem libraries and just copy & paste into a secure execution environment. It was a huge success at my last company.

I'm very thankful to Laurent Le-brun and Alan Donovan -- both of whom are exceptional engineers that I learned so much from. I thought I was skilled but both of those individuals are just on another level.