Let inference do the boring work
Decide when to rely on TypeScript inference and when to write an explicit annotation.
The move: Put annotations where they change what a reader can trust. TypeScript infers types from values, context, and control flow. That means a local constant initialized from a literal or a typed helper usually does not need a manual label. Repeating the obvious has a cost: the eye stops noticing the annotations that matter. Use explicit types at seams. A function parameter says what callers may pass. A return type on exported code says what downstream code can rely on. An API response, JSON.parse, a route param, or a third-party callback is a trust boundary; the compiler cannot infer…
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