My job is to doing due diligence on tech companies during major investments and acquisitions, and one of the most successful (and interesting) I've seen was doi

My job is to doing due diligence on tech companies during major investments and acquisitions, and one of the most successful (and interesting) I've seen was doing exactly what you describe. It wasn't Racket, but the code base was an engine with a very sophisticated DSL enabling all their in-house domain experts to work hyper-productively. Their work was split into an engine, which their low level super-senior hackers worked on, and the assets, which were the things customers bought and were made in a DSL by highly educated domain experts. It was really impressive, and they are doing very well. I've long been convinced that this is the logical highest level of "onion/hexagonal/ports and adapters" architecture, and seeing what they had done was really cool.