Design a Feature Flag for Shopify
Last updated: December 7, 2025
Quick Overview
Design a event-driven feature flag system that handles millions of requests. Discuss trade-offs in consistency, availability, and performance.
Shopify
December 7, 202549
13
3,805 solved
Design a event-driven feature flag system that handles millions of requests. Discuss trade-offs in consistency, availability, and performance.
Shopify 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
- Clearly define functional and non-functional requirements
- Propose a reasonable high-level architecture with core components
- Choose appropriate data storage solutions with basic justification
- Discuss basic scaling strategies (horizontal scaling, caching)
- Identify potential bottlenecks and suggest simple solutions
Key Topics to Cover
How to Approach This
- Start by clarifying functional and non-functional requirements with the interviewer.
- Estimate the scale: QPS, storage, bandwidth. This drives your design decisions.
- Draw a high-level architecture first, then deep dive into 1-2 critical components.
- Discuss trade-offs explicitly (e.g., consistency vs availability, SQL vs NoSQL).
- Address failure scenarios, monitoring, and how the system handles 10x traffic spikes.
Possible Follow-up Questions
- How would you implement rate limiting to protect the system?
- How would you handle schema migrations with zero downtime?
- What would the deployment pipeline look like for this system?
- How would you optimize costs as the system scales?
Practice a Similar Problem on Codemia
Solve a related problem with our interactive workspace, get AI feedback, and view detailed solutions.
Solve on CodemiaSample Answer
Requirements
Functional Requirements
- Feature Toggle Management: Admins can create, update, and delete feature flags via a web interface.
- User Targeting: Ability to target specific user segments (...
Capacity Estimation
Assuming Shopify has 1 million active merchants, each performing an average of 100 feature flag checks per second during peak hours:
- Total requests per second (RPS): 1,000,000 merchants * 100 RP...
Submit Your Answer
