Why discarding sensor metadata at write time creates permanent data blind spots

A software engineer writing for DEV Community argues that most database schemas silently discard critical reliability signals — such as GPS accuracy radius, location provider, and sensor confidence — that accompany real-world data at the time of collection. Using a location-tracking app as a case study, the author shows how an initially minimal schema led to unanswerable questions months later about journey quality and data integrity. The core problem is irreversibility: once a row is written without confidence metadata, that information cannot be recovered or backfilled for any future query. The author's solution was to expand the schema into three groups — the raw reading, trust indicators, and pre-computed verdicts — alongside a 0–100 condition score summarising tracking quality. The takeaway is that storing doubt alongside data is cheap upfront but effectively impossible to retrofit after the fact.