React-query

Why a declarative auth gate and an imperative router.replace inevitably flicker when they coexist — and how one hidden timing fact (derived state flips before the promise resolves) amplifies the double-driver into a visible regression.

React uses reference equality, not value equality, to detect dependency changes — how that low-level semantic turns a harmless empty-array fallback into an infinite setState loop, and why the same code is merely wasteful on the web but fatal on mobile.

Why async/await on this one specific queryFn boundary turns an already-resolved value into undefined on Hermes — and how silent fail-soft disguises it as a harmless feature flag.