Hellandizing (1998)
multicians.org
multicians.org
It is interesting to speculate (I wasn't an active programmer then) that this is what the world looked like before TDD.
There may not have been unit tests. Your automated test coverage might have been 0%. So when it came to knowing whether your program worked - you went in and broke it.
I don't think for most regular systems that this is what the world of testing looked like in the 90s (definitely not from my perspective at the time - I was neck-deep in a VB5 project then).
This does seem like an interesting method of testing, though, for those Tandem systems. I'm not sure if those systems are still available today, but I wouldn't doubt that there are examples still running (likely banking/financial sector - where IIRC is where they were mostly used).
http://infohost.nmt.edu/~al/cseet-paper.html
https://www.eiffel.com/values/design-by-contract/introductio...