Algebraic Types: Preventing Bugs in Distributed System State

Distributed systems inherently manage multiple concurrent states, and using loose modeling approaches like booleans can inadvertently create invalid combinations such as a node being both leader and recovering simultaneously. Algebraic types, particularly enums and sum types, force the compiler to ensure only one valid state can exist at a time, eliminating entire classes of correctness bugs. This transforms state management from a source of subtle bugs into a compiler-enforced guarantee of correctness.