Which answer is correct?

Use `interface` for object shapes and `type` for unions, intersections, and aliases. Interfaces support declaration merging and are slightly better for performance in large projects.

— ts_pragmatist

Always use `type`. It's more powerful — it can do everything `interface` can, plus unions, mapped types, and conditional types.

— type_maximalist

Always use `interface`. It's the original TypeScript way and `type` was added later as a workaround.

— classic_ts

They're completely interchangeable. Pick one and be consistent.

— just_pick_one