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Google·Technical Product Manager·Onsite - System Design / Architecture·Staff

Staff
Jun 2026

Summary

Google TPM system design round, one meaty question about data center fault handling. Pretty open-ended and I spent the first few minutes just trying to figure out what scope they actually wanted.

Questions Asked (1)

Q1

Design a technical system that automatically detects and replaces faulty hardware components in a data center.

System DesignTechnical Trade-offsCross-functional Alignment
Author's notes

I jumped straight into fault detection and kind of ignored the replacement logistics side for too long.

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AI HintsAI Generated

Suggested Approach

Start by clarifying the scope and requirements with the interviewer, then outline a high-level system architecture that covers detection, decision-making, and replacement. Emphasize the trade-offs between automation and manual intervention, and how you would align cross-functional teams to implement and operate the system.

Pro tip: Focus on the product perspective: define clear success metrics (e.g., reduction in downtime, cost savings) and discuss how you would prioritize features based on impact and feasibility. Show that you understand the operational challenges and the need for gradual rollout with safety checks.

1. Clarify Requirements and Scope

Ask questions to understand the scale (number of servers, components), types of hardware, acceptable downtime, and existing monitoring tools. Define what 'faulty' means and the desired automation level.

2. Design Detection Mechanism

Propose a system that collects telemetry (e.g., SMART data, error logs, performance metrics) and uses anomaly detection or rule-based thresholds to identify faulty components. Consider both predictive and reactive detection.

3. Decision and Orchestration

Outline how the system decides to replace a component: automated vs. human-in-the-loop, prioritization based on severity, and scheduling replacements to minimize impact. Include integration with ticketing and inventory systems.

4. Replacement Execution

Describe the process for physically or logically replacing the component: robotic automation, technician dispatch, or software failover. Address safety, validation, and rollback procedures.

5. Monitoring and Feedback Loop

Explain how the system tracks success rates, false positives, and overall performance. Use this data to improve detection algorithms and operational processes.

Key Points to Mention

  • Trade-offs between full automation and human oversight (cost, reliability, safety)
  • Integration with existing data center infrastructure (monitoring, ticketing, inventory)
  • Scalability and fault tolerance of the detection system itself
  • Cross-functional collaboration (hardware teams, SREs, data scientists, operations)
  • Metrics for success (MTTR, downtime reduction, cost per replacement)
  • Phased rollout and risk mitigation (pilot testing, gradual automation)

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