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Google·Product Manager·Onsite - System Design / Architecture·Senior

Senior
May 2026

Summary

Google PM interview, one question on system design for a ticketing platform. Pretty open-ended and I wasn't totally sure how deep to go on the technical side versus the product side.

Questions Asked (1)

Q1

How would you design the system for a ticket selling web application?

System DesignTechnical Trade-offsProduct Sense & Ideation
Author's notes

I spent the first few minutes trying to figure out whether they wanted a PM-style answer or an actual architecture breakdown.

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AI HintsAI Generated

Suggested Approach

Start by clarifying the scope and goals of the ticket selling system, then structure your answer around key components like user flows, inventory management, and scalability. Focus on product trade-offs and how you would prioritize features to balance user experience with business needs.

Pro tip: Emphasize the importance of handling high-concurrency scenarios and preventing overselling, as these are critical for ticket systems and demonstrate deep product thinking. Also, tie your design decisions back to user trust and fairness, which are paramount in ticketing.

1. Clarify Requirements and Scope

Ask questions to understand the scale, user types (e.g., event organizers, attendees), and key features like seat selection, payment, and anti-fraud measures. Define success metrics such as sell-through rate and user satisfaction.

2. Outline Core User Flows

Map out the end-to-end journey for buyers and organizers, including browsing events, selecting tickets, checkout, and post-purchase actions. Identify pain points and opportunities for differentiation.

3. Design System Components and Trade-offs

Propose high-level architecture covering inventory management, payment processing, and scalability. Discuss trade-offs between consistency and availability, and how to handle peak loads.

4. Address Edge Cases and Risks

Consider scenarios like bots, scalping, payment failures, and refunds. Explain how your design mitigates these risks and ensures fairness.

5. Prioritize and Iterate

Suggest an MVP and a roadmap for future enhancements based on user feedback and business impact. Highlight metrics to track and iterate upon.

Key Points to Mention

  • High concurrency and scalability: use of queues, load balancing, and distributed systems to handle traffic spikes.
  • Inventory consistency: preventing overselling through locking mechanisms or reservation systems.
  • Payment integration and security: PCI compliance, fraud detection, and seamless checkout.
  • User experience: intuitive seat selection, mobile optimization, and transparent pricing.
  • Anti-bot and fairness measures: CAPTCHAs, queue systems, and limits per user.
  • Data and analytics: tracking user behavior to optimize pricing, marketing, and inventory allocation.

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