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Amazon·Machine Learning Engineer·Onsite - System Design / Architecture·Senior

Senior
May 2026

Summary

System design round at Amazon for an ML engineer role. The whole question was about building a validation pipeline for LLMs, covering everything from tensor-level checks to human review. Pretty broad scope for one question.

Questions Asked (1)

Q1

Design an end-to-end quality validation system for a team that trains and serves large language models. The system should automatically evaluate correctness, safety, and regression risk across new model versions and live production responses.

System DesignTechnical Trade-offsProduct Analytics & Metrics
Author's notes

This one sprawled fast.

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AI HintsAI Generated

Suggested Approach

Start by clarifying requirements and constraints (latency, cost, scale, safety thresholds), then propose a layered architecture with offline evaluation, online monitoring, and automated regression gates. Emphasize trade-offs between automated metrics and human review, and how to handle evolving safety definitions.

Pro tip: Anchor your design around a golden dataset that is versioned and continuously expanded with production edge cases, and propose a canary deployment with automated rollback based on safety and quality metrics. This shows you understand both model lifecycle and operational risk.

1. Clarify Requirements and Constraints

Ask about scale (QPS, model size), latency budgets, safety definitions, regulatory requirements, and existing infrastructure. Establish what 'correctness' and 'safety' mean for this team.

2. Design Offline Evaluation Pipeline

Propose a versioned golden dataset with diverse prompts covering correctness, safety, and edge cases. Define automated metrics (e.g., exact match, BLEU, toxicity scores, bias detection) and human-in-the-loop review for ambiguous cases.

3. Implement Online Monitoring and Regression Detection

Deploy shadow mode and canary releases with real-time metrics (latency, error rates, safety violations). Use statistical tests to compare new vs. baseline models and trigger alerts on regressions.

4. Automate Gates and Rollback

Define thresholds for promotion (e.g., >95% on golden set, <0.1% safety violations) and automate rollback if canary metrics degrade. Integrate with CI/CD for model deployment.

5. Iterate and Improve with Feedback Loops

Continuously mine production data for new edge cases, update golden datasets, and refine metrics. Use A/B testing to measure business impact and adjust safety thresholds.

Key Points to Mention

  • Golden dataset versioning and expansion with production data
  • Automated metrics for correctness (e.g., exact match, semantic similarity) and safety (e.g., toxicity, bias, PII leakage)
  • Human-in-the-loop for ambiguous or high-risk cases
  • Canary deployments and shadow mode for safe rollout
  • Statistical significance and regression detection (e.g., sequential testing)
  • Trade-offs between latency, cost, and thoroughness of evaluation
  • Integration with CI/CD and automated rollback

AI-generated suggestions, not part of the candidate's original notes. May be inaccurate — verify before relying on them.