Everything Should Be Typed: Scalar Types Are Not Enough

2026-04-15

Using only scalar types (like string or int) provides weak guarantees because they capture shape but not meaning, allowing subtle bugs like swapped IDs or units to compile and slip through. Wrapping domain concepts in distinct types (newtypes) makes invalid states unrepresentable, enabling the compiler to enforce correctness, improve safety, and encode business logic directly into the type system.