What is real-time feature store in recommendation systems?

Updated May 16, 2026

Short answer

A feature store manages and serves features consistently for training and serving.

Deep explanation

Feature stores ensure that offline training and online inference use identical feature definitions. Real-time feature stores update user behavior signals instantly and serve them with low latency for ranking models.

Real-world example

TikTok updating user interest vectors in real time.

Common mistakes

  • Training-serving skew due to inconsistent features.

Follow-up questions

  • What is training-serving skew?
  • Why feature store is needed?

More Recommendation Systems interview questions

View all →