[SatvikBeri]

I've done two DSLs in my career.

One was for a visual novel video game, where the designers had relatively detailed specs. They had been manually translating those to code, but that was tedious and pretty far outside their expertise. I was contracted to translate those specs into code. I ended up mostly writing a script to turn their specification language into a more structured representation, then translate that into code, with a bit of back & forth to make their language more precise. From everything I heard this was a big success, my script saved them a lot of hours, and the game was pretty successful by the standards of indie games.

The other...is not exactly a DSL, but I don't know what to call it. We had researchers who were writing a lot of numeric code to try and find signals in data. This code often worked, but was slow and expensive to run at large scale, in part because it would have to recalculate intermediate values over and over again. So we wrote a "DSL" that had almost exactly the same syntax as the code they were writing, but was lazy and created a DAG rather than immediately executing, and eventually used the DAG to execute much more efficiently.