Glossary
Feature store
A centralized system that stores, versions and serves machine learning features so training and live prediction use identical definitions.
A feature store is a centralized system for storing, versioning and serving the features used to train and run machine learning models, built to solve a specific problem: the code that computes a feature for model training and the code that computes it for live predictions are often written separately and can drift apart, quietly breaking model accuracy.
A feature store typically has two sides: an offline store, holding historical feature values for training data, and an online store, serving the latest value for a given entity, such as a customer, with low latency at prediction time. Both are computed from the same underlying feature definition, so what a model saw during training matches what it sees in production, avoiding what practitioners call training-serving skew.
Feature stores matter because they let feature engineering work be defined once and reused across models and teams, instead of being reimplemented per project, and they make features easier to check for data drift over time. They are a core piece of MLOps tooling; teams without one often rebuild feature logic by hand for each model, increasing the risk of subtle mismatches between training and serving.
Last reviewed September 22, 2026