I haven’t had a bug in production for 9+ years. Not a single one. And routinely do major refactorings, feature improvements, optimisations etc. I can do it beca

I haven’t had a bug in production for 9+ years. Not a single one. And routinely do major refactorings, feature improvements, optimisations etc. I can do it because of 9000+ tests. 1800 hand written and the rest auto generated to detect changed behaviour. The test suite allows me to spend 95% of my time adding features instead of bug fixing. Most excellent.