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Machine Learning February 5, 2025 10 min read

ML System Design Interview: A Framework That Works

A structured approach to ML system design interviews — problem framing, data strategy, modeling choices, serving infrastructure, and monitoring.

The 6-Step Framework

1. Problem Framing (5 min)

  • What is the exact business objective?
  • What does success look like (KPI)?
  • Is this supervised? Online or batch?

2. Data Strategy (5 min)

  • What data exists? Volume, freshness, quality?
  • How to handle missing labels?
  • Privacy/compliance constraints?

3. Feature Engineering (10 min)

  • Raw features available
  • Computed/aggregated features
  • Embedding features (text, images)

4. Modeling (10 min)

  • Baseline (rule-based)
  • ML approach (gradient boosting / NN)
  • Evaluation metric and why

5. Serving (10 min)

  • Batch or real-time?
  • Latency requirements
  • Feature store design

6. Monitoring (5 min)

  • Data drift, concept drift
  • A/B testing plan
  • Retraining trigger
System DesignML InterviewArchitectureProductionCareer
O

Ossama Elhakki

AI Engineer & ML Systems Builder — Morocco