Design Rate Limiting Infrastructure for mobile apps
Last updated: November 5, 2025
Quick Overview
Design a low-latency rate limiting system that handles millions of requests. Discuss trade-offs in consistency, availability, and performance.
Tesla
November 5, 2025147
7
1,705 solved
Design a low-latency rate limiting system that handles millions of requests. Discuss trade-offs in consistency, availability, and performance.
System design interviews at Tesla typically last 45-60 minutes. You are expected to drive the conversation, starting from requirements gathering through to a detailed architecture. The interviewer will evaluate your ability to handle ambiguity and make practical engineering decisions.
What the Interviewer Expects
- Drive the design discussion proactively with minimal interviewer guidance
- Perform detailed capacity estimation and use it to inform design decisions
- Design for global scale with multi-region deployment and data consistency
- Deep dive into 2-3 critical components with implementation-level detail
- Address complex trade-offs: CAP theorem, eventual consistency, conflict resolution
- Discuss operational excellence: deployment strategy, chaos engineering, SLOs/SLIs
- Propose a phased rollout plan from MVP to full-scale system
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
- What happens if one of your database nodes goes down?
- How would you implement rate limiting to protect the system?
- How would you handle a region-wide outage?
- How would you migrate from a monolithic to a microservices architecture?
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:
- The system must limit the number of requests per user (or IP) to prevent abuse while ensuring legitimate users have a smooth experience.
- Support for multiple rat...
Capacity Estimation
Assuming Tesla's mobile app has approximately 10 million active users:
- If each user makes an average of 100 requests per day, the total request volume would be:
- 10,000,000 users * 100 requests =...
Submit Your Answer
