There are the kinds of defects that people notice, and then there are the kinds of defects that people don't notice. Crashes are usually noticed, while nonsense

There are the kinds of defects that people notice, and then there are the kinds of defects that people don't notice. Crashes are usually noticed, while nonsense calculations and undefined behavior are sometimes not noticed. I worked at a company that sold a product that some customers used to make decisions involving a lot of money. A program misbehaved, or gave the wrong answer, or returned from a function too soon, or something. It didn't crash. A customer lost a lot of money, and we were liable. It turned out that the bug was a symptom of undefined behavior that would have been caught by one of the flavors of assertions built into standard releases of the core C++ libraries. The team in charge of the app in question had long ago disabled those assertions because "they keep crashing the code." Infrastructure within the company then went through a small internal crisis about whether to force assertions down people's throats or to let it be wrong on prod. The compromise was to have the assertions expand to loud warnings on prod. Ops then had a tool that would list all of the "your code is provably broken" instances, and that went to a dashboard used the shame the relevant engineering managers. Not sure if it worked, but when you have a _lot_ of C++ code, a great deal of it is broken and "it's fine." Until it isn't.