Good old cucumber. I remember a discussion over coffee with someone who swore by it back in the day (~2010). They forced customers to sit down and write these things together side by side. Kind of cringe in retrospect. Wonder what happened to them.

Business people don't really care about this stuff. Over the years I realize more and more that we engineers are naive in thinking that business side is concerned with edge cases and race conditions.

Just to give an analogy software people might get better, if you come to a lawyer because, say, you want to buy a house, you are not going to sit down with them and say "given I want to buy a house, when the seller hides water damage costing over $2000, I get to walk away from the deal". You just hope the lawyer is good and will protect you from various edge cases. You have a lot more to deal with than just closing paperwork. You probably are thinking about renovating, moving, getting inspection, etc.

Businesses are just like that with engineering. They don't want to sit down and meticulously analyze every possible edge case. They have other things to do. Especially when stakes are not that high. Most of these errors can probably be resolved with a phone call and a database edit.

I think this is probably for the best. A good engineer will make sure you're standing on a solid ground, and ask the right questions at the right time. They wouldn't need this amount of hand holding. Leave business time to focus on making deals, connections, organizing the whole operation to move forward, etc. Let them give you vague requirements, and crystallize them yourself. It's way better than a micro-managing business that thinks they know exactly how everything should be.

P.S. Also, I'm not sure why everyone is so hung up on regex = bad, it's not like switching to an AST-based language would've made anything better here. Regex is fine imo, just the entire concept isn't.