Feature Store
The pattern: define features once; serve them at training (offline, point-in-time-correct) and at inference (online, low-latency). The same definition, two materializations. Solves train-serve skew structurally and unlocks feature reuse, freshness SLOs, lineage, and governance as platform-level concerns.
The trade-off: infrastructure complexity vs. skew prevention. A feature store is real infrastructure — offline store, online store, registry, materialization scheduler. For a single-model team, the overhead rarely pays off. For a platform hosting many models with shared features, one definition shared across ten consumers — with the same correctness guarantees on both sides — is the entire point.
Deepens in Year 4 Phase 22: Feature Store — Feast on Iceberg with a Redis online store, defining commits-per-repo features for personal-api consumers. Reinforced in Phase 25: GPU Infrastructure when drift detection closes the loop.
Related patterns
- train-serve-skew — the failure mode this pattern exists to prevent.
- model-lifecycle — the lifecycle stages that consume offline and online feature views.
- inference-shapes — online vs. batch consumption maps onto the two materializations.
- snapshot-plus-delta — point-in-time correctness on the offline side leans on this.
- oltp-vs-olap — online (OLTP-shaped key lookup) vs. offline (OLAP-shaped scan) is the underlying split.
- tool-use-as-capability — common backing store behind retrieval tools.
- Phase 24: LLM Infra + RAG — vector index alongside feature store for hybrid retrieval.
basecamp— where Feast lives in the platform stack.mlship— consumer of online features at inference time.