Type systems limit the set of programs accepted by the compiler. A sound type system will reject every bad program - but also may reject some good programs. Typ

Type systems limit the set of programs accepted by the compiler. A sound type system will reject every bad program - but also may reject some good programs. Type systems therefore also will have escape hatches to let the programmer overrule the compiler. Bad type systems need you to use the escape hatches frequently - you can't write much C without using casts. I haven't yet used a language with no need at all for an escape hatch - but some languages need them far less often than others. Java's type system is better than it was. The main places it still has weaknesses are around exceptions (you will need to wrap checked exceptions in runtime exceptions in places you'd have preferred to specify an exception type via generics, eg) and the occasional cast after an instance type check. You can phrase good development practices in business terms: what are the risks to the business due to sloppy code? Are they greater than the risk of being slow to market? Sloppy code has accumulating costs. A good type system can help greatly with refactoring to address those costs, but it cannot help with the attitude that those costs aren't real and don't need to be paid.