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Meta·Software Engineer·Onsite - System Design / Architecture·Senior

Senior
Apr 2026

Summary

Round 5 at Meta for a software engineer role, and they threw an AI system design question at me about building an agent to manage failures in a large-scale pipeline. Pretty deep into the process at that point so the stakes felt real.

Questions Asked (1)

Q1

Design an AI agent that can detect and handle issues in a large-scale data or processing pipeline.

System DesignTechnical Trade-offsAdaptability & Ambiguity
Author's notes

This one had a lot of surface area and I spent probably too long on the detection side before even touching remediation.

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AI HintsAI Generated

Suggested Approach

Start by clarifying the scope and requirements of the pipeline and the AI agent's role, then propose a high-level architecture that combines monitoring, anomaly detection, and automated remediation. Discuss trade-offs between rule-based and ML-based approaches, and how to ensure scalability, reliability, and safety in a large-scale environment.

Pro tip: Emphasize the importance of starting with a simple, interpretable baseline (e.g., threshold-based alerts) before introducing ML, and always include a human-in-the-loop for critical decisions to build trust and avoid catastrophic automated actions.

1. Clarify Requirements and Scope

Ask questions to understand the pipeline's scale, data volume, latency requirements, and what types of issues need detection (e.g., data drift, failures, performance degradation). Define success metrics and constraints.

2. Design the Detection System

Propose a multi-layered detection approach: use statistical methods and rules for known issues, and ML models (e.g., anomaly detection, time-series forecasting) for unknown patterns. Discuss feature engineering from logs, metrics, and traces.

3. Design the Handling and Remediation

Outline automated actions (e.g., restarting services, scaling resources, alerting) and when to escalate to humans. Include a feedback loop to improve detection over time.

4. Address Scalability and Reliability

Explain how the agent will handle high throughput, avoid single points of failure, and ensure low-latency detection. Discuss distributed processing, streaming vs. batch, and model serving considerations.

5. Discuss Trade-offs and Evaluation

Compare rule-based vs. ML-based approaches, precision vs. recall, and automation vs. human oversight. Describe how to evaluate the agent's performance (e.g., A/B testing, offline metrics) and iterate.

Key Points to Mention

  • Use of streaming data processing frameworks (e.g., Apache Kafka, Flink) for real-time detection
  • Anomaly detection techniques: statistical methods (e.g., z-score, IQR) and ML models (e.g., isolation forests, autoencoders)
  • Integration with existing monitoring tools (e.g., Prometheus, Grafana) and alerting systems
  • Automated remediation strategies: self-healing, auto-scaling, and rollback mechanisms
  • Human-in-the-loop for critical decisions and continuous feedback for model improvement
  • Trade-offs between false positives and false negatives, and how to tune thresholds accordingly

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