Meta·Technical Product Manager·Onsite - System Design / Architecture·Senior

Senior

Apr 2026

Summary

Meta TPM system design round, just one question about building a voting system. Not a lot of context given upfront, so most of the work was figuring out what kind of voting system they even wanted.

Questions Asked (1)

Design a voting system.

System DesignTechnical Trade-offsAdaptability & Ambiguity

Author's notes

Wide open question and I spent probably too long asking clarifying questions before drawing anything out.

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AI HintsAI Generated

Suggested Approach

Start by clarifying the scope and requirements of the voting system, such as scale, types of elections, and key constraints. Then outline a high-level design covering user flows, data model, and system components, and dive into critical trade-offs like consistency vs. availability and security vs. usability. Finally, discuss how you would measure success and iterate based on metrics and user feedback.

Pro tip: Anchor your design in Meta's scale and social context—consider how features like social sharing, identity verification, and real-time engagement could influence the voting experience. Also, proactively address potential abuse and misinformation, as these are top-of-mind for Meta.

1. Clarify Requirements and Scope

Ask questions to understand the type of voting (e.g., political elections, polls, contests), scale (number of users, votes per second), and key constraints (security, privacy, regulatory). Define functional and non-functional requirements.

2. Outline High-Level Design

Sketch the main components: user interface, authentication, vote casting, vote storage, tallying, and results display. Consider how users will access the system (web, mobile) and how votes will be secured and verified.

3. Deep Dive into Critical Components

Choose 1-2 areas to detail, such as data consistency (e.g., using a distributed ledger or database with strong consistency), scalability (sharding, caching), and security (encryption, audit logs). Explain trade-offs.

4. Address Trade-offs and Edge Cases

Discuss trade-offs like consistency vs. availability, anonymity vs. verifiability, and cost vs. performance. Cover edge cases: duplicate votes, fraud, system failures, and how to handle recounts.

5. Define Success Metrics and Iteration Plan

Propose metrics like participation rate, system uptime, vote integrity, and user satisfaction. Outline how you would launch, monitor, and iterate based on feedback and data.

Key Points to Mention

Scalability: handling millions of concurrent users and votes with low latency
Security: preventing fraud, ensuring vote integrity, and protecting user privacy
Consistency and availability trade-offs: CAP theorem implications for vote tallying
User experience: simple, accessible voting flow with clear feedback
Regulatory and compliance considerations: data retention, auditability, and accessibility standards
Abuse prevention: rate limiting, identity verification, and anomaly detection

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