DeepOffer

Architect a Shared Platform for Creating and Serving Features

ML System DesignHot interview question
Reported in public interview compilations — Uber, Netflix, LinkedIn, Airbnb, Pinterest, Spotify

Problems to solve first: Duplicate feature work, online/offline inconsistency, and training-serving skew (point-in-time misalignment). The platform's value is these three things.

Dual storage: Offline store (data warehouse / lakehouse, time-partitioned history for training and backfills) plus online KV (low-latency point lookups for inference). One feature definition, written to both.

Point-in-time correctness: When building training samples, you must look up the feature value as of the sample timestamp - otherwise you leak the future. This is the core and hardest part to explain well.

Governance: feature registry and lineage, versioning, freshness SLAs, and reuse rate. Interviewers want to hear not just storage, but who uses it and how you prevent it from rotting.

Common follow-up questions

Practice this question with an AI interviewer

Get asked follow-ups live, then receive a scored report — like a real MLE interview loop.

Start AI mock interview