One example of this is video game designer and programmer Jonathan Blow, best known for creating the game Braid.
https://en.wikipedia.org/wiki/Braid_(video_game)
He's working on a language for writing games.
https://www.gamesindustry.biz/articles/2018-07-02-jonathan-b...
https://www.reddit.com/r/programming/comments/7okvam/jai_lan...
https://www.reddit.com/r/programming/comments/8ywd77/gamelab...
https://www.reddit.com/r/programming/comments/89209l/jonatha...
Here is one of many videos of him using the language:
https://www.youtube.com/watch?v=AAFkdrP1CHQ
A couple of moments in that video which I would like to highlight:
At 11:15, responding to a question from chat:
> Is there a specific reason the game is kind of in top-down 3D?
> Because that is what helps the game mechanics that we need for this game. If it was in first-person (laughs)... it would be kind of amusing... maybe we should do that (smiles) that'd be fun.
At 14:05, responding to another question from chat:
> Do I find the language scaling, well, now that I am dealing with a more complex program?
> Yes. I've been dealing with a program this complicated for like five or six months so this is nothing new.
At 14:15, responding to another question from chat:
> Do I have my own shader language?
> No, right now we are using OpenGL and [unintelligible] GLSL.
The answer to this third question indicates to me that he is focusing on getting something that works better for him than pre-existing alternatives without getting bogged down too much that every side of his language needs to be perfect right off the bat.
In other words, he is balancing the time to perfect his language against the time he wants to spend making games rather than spending 100% of his time working on the tooling and not getting to write any games.