React Performance: Rerender — Narrow Dependencies. Keywords: effect dependency primitive. Platform: React/Next.js. Description: Specify primitive dependencies instead of objects in effects. Do: Use primitive values in dependency arrays. Don't: Use object references as dependencies. Good Example: useEffect(() => { console.log(user.id) }, [user.id]). Bad Example: useEffect(() => { console.log(user.id) }, [user]). Severity: Low.