Interface anti-patterns

Interfaces can become extremely powerful, but only if they remain semantically coherent.

Anti-patterns

Anti-pattern	Why it hurts	Better alternative
giant catch-all interfaces	destroys reuse clarity	make interfaces narrowly purposeful
interfaces that duplicate one object type exactly	adds indirection with no reuse	keep logic on the object type unless reuse is real
using interfaces as loose tags only	misses semantic structure	give interfaces explicit properties and meaning
attaching too many unrelated interfaces	creates semantic confusion	compose only when behaviors truly align

Design rule

An interface should describe a reusable operational trait, not an arbitrary bucket of fields.