Mutability, Equality, and the Hidden Cost of Convenience

Mutability

Mutable state increases cognitive load over time.

t0: X → t1: Y → t2: Z

Equality

Equality can mean structure, identity, or semantics.

Concurrency

Concurrency exposes weak abstractions.

Thread A ─┐
          ├─ Shared State → Bug
Thread B ─┘

Takeaway

Clear ownership and immutability scale better.