I've heard this expressed as "write brittle code", and I'm a strong advocate for it. Looking up a user by id, and get no results? Rather than either passing nul

I've heard this expressed as "write brittle code", and I'm a strong advocate for it. Looking up a user by id, and get no results? Rather than either passing null up the stack, or wrapping null with an optional.empty, throw an exception! It's the client code's problem if it somehow got hold of an id that doesn't exist. (Yes, ymmv depending on the system, e.g. if you're dealing with eventual consistency then maybe do something different.) As the article says, this of course doesn't mean that you shouldn't handle user errors, or even known system errors.