[jordhy]

There is something called UML -- this is a dying though There was something called Rational Rose -- maybe it still exists somehow

Today we use wireframes and Adobe XD mock up as most of the products are mobile/web-based.

The formal specification of software practice started to fade when product managers came into the software development lifecycle. Back in the day, technical managers and information architecs would make detailed specs detailing everything about an upcoming platform. Only to see have of it be change by a manager/business stakeholder.

Today the push is for speed and cost reduction - fail fast and break things. It's really not as bad as it sounds but way worst.