I started my career at CMG, a big consultancy now called Logica. They were BIG on UML and Rational Unified Process. I had no clue what I was doing so I gobbled

I started my career at CMG, a big consultancy now called Logica. They were BIG on UML and Rational Unified Process. I had no clue what I was doing so I gobbled it up. "So THIS is how you make software, ahaaaaaaa!" After leaving CMG I have never, ever seen it used in the wild by any remotely successful company or team. I would say it is a clear red flag even. Sequence diagrams are the only thing I sometimes use to get a grip on how APIs should talk to each other or how flows between integrations should be.