Design a high-throughput Feature Flag System

Last updated: July 12, 2025

Quick Overview

Design a high-throughput feature flag system that handles millions of requests. Discuss trade-offs in consistency, availability, and performance.

Anthropic
System Design
Software Engineer
Anthropic
July 12, 2025
Software Engineer
System Design Round
System Design
Medium

1

13

2,623 solved


Design a high-throughput feature flag system that handles millions of requests. Discuss trade-offs in consistency, availability, and performance.

Anthropic asks this during the System Design Round to assess your architectural thinking. They want to see how you decompose a complex problem, choose appropriate technologies, and reason about failure modes. Strong candidates proactively discuss monitoring, alerting, and operational concerns.

What the Interviewer Expects
  • Systematically gather requirements and estimate capacity (QPS, storage, bandwidth)
  • Design a scalable architecture with clear component responsibilities
  • Make well-reasoned database and caching decisions with trade-off analysis
  • Address consistency vs availability trade-offs specific to the use case
  • Discuss partitioning strategy, replication, and data modeling
  • Cover failure handling, monitoring, and alerting strategies
Key Topics to Cover
API design and rate limiting
Security and authentication
Monitoring, logging, and alerting
Caching strategies (local, distributed, CDN)
How to Approach This
  1. Start by clarifying functional and non-functional requirements with the interviewer.
  2. Estimate the scale: QPS, storage, bandwidth. This drives your design decisions.
  3. Draw a high-level architecture first, then deep dive into 1-2 critical components.
  4. Discuss trade-offs explicitly (e.g., consistency vs availability, SQL vs NoSQL).
  5. Address failure scenarios, monitoring, and how the system handles 10x traffic spikes.
Possible Follow-up Questions
  • What would the deployment pipeline look like for this system?
  • How would you implement rate limiting to protect the system?
  • How would you migrate from a monolithic to a microservices architecture?
  • What happens if one of your database nodes goes down?
Practice a Similar Problem on Codemia

Solve a related problem with our interactive workspace, get AI feedback, and view detailed solutions.

Solve on Codemia
Sample Answer
Requirements Clarification

Before diving into the architecture, clarify the scope with the interviewer. For high-throughput Feature Flag System, key functional requirements incl...

Capacity Estimation

Estimate the scale to drive design decisions. Assume 100M DAU with an average of 10 actions per user per day = 1B requests/day ~ 12K QPS average, ~36K...


Submit Your Answer
Markdown supported

Related Questions