HoloCore

HoloCore owns every external boundary for HoloMetrics and Watchtower. It ingests pricing data, product metadata, and inventory state from sources that disagree with each other, resolves them into one schema, and serves the result through a Fastify API.

Normalisation is the whole problem here. Feeds identify the same product differently, publish at different cadences, and change format without notice, so ingestion assumes inconsistency by default rather than treating it as an error to be handled later on.

Identity resolution runs across sources, validation happens at every boundary, and pipelines degrade to stale-but-correct when a provider goes dark. A price that is wrong is worse than one that is late, so neither application ever sees an upstream provider's shape.