Day 123 of 133

Privacy-preserving ML (federated, DP, on-device) + DSA review

When each is the right answer; cost in accuracy.

DSA · NeetCode Intervals

  • Interview questions to prep

    1. Do you sort by start or by end? Defend the choice based on the invariant you need.
    2. Walk through merge / overlap detection: what's your condition for 'overlapping'?
    3. How does complexity break down: O(n log n) sort + O(n) sweep — can you do better in any case?

ML System Design · Cross-cutting trade-offs

  • Interview questions to prep

    1. What levers do you pull when accuracy is great but latency misses the budget?
    2. Walk through where you'd add caching in a RAG + LLM pipeline to halve P99.
  • Multi-model routing & cascadesML System DesignAnyscale

    Interview questions to prep

    1. How would you design a cascade: cheap model first, expensive only when needed?
    2. What's the right verifier for the cheap model's output — and when does it dominate cost?
  • Interview questions to prep

    1. Walk through cold-start strategies for new users vs new items.
    2. Compare bandit-based exploration vs content-based bridges for cold start — when does each fit?
  • Interview questions to prep

    1. When would you reach for federated learning vs differential privacy vs on-device inference?
    2. What's the accuracy cost of DP-SGD at typical ε values, and how do you decide if it's acceptable?

MLOps · Privacy & security

  • Interview questions to prep

    1. How would you remove PII from training data without destroying signal?
    2. Compare hashing vs tokenization vs full redaction for PII fields — when does each fit?
  • Differential privacy basicsML System DesignGoogle

    Interview questions to prep

    1. Explain differential privacy in one minute — what does ε mean?
    2. How does DP-SGD differ from regular SGD, and what does it cost in accuracy?
  • Federated learningML System DesignGoogle

    Interview questions to prep

    1. When is federated learning the right choice over centralized training?
    2. What are the systems-side challenges in federated learning beyond the algorithm?
  • Interview questions to prep

    1. What is a model-extraction attack, and how do you mitigate it?
    2. How would you defend a public ML API from membership-inference attacks?

References & further reading