Founder of https://interval.com here. We're somewhere in-between Retool and Windmill which was mentioned on this thread.

Like Windmill, Interval is heavily code-focused. Our model lets you define tools in your existing TypeScipt/JavaScript codebase.

Like Retool, you can use Interval to build complete internal dashboards that handle the "view stuff" side of things, not just the script/workflow "do stuff" pieces.