Architect a event-driven Logging Engine
Last updated: August 13, 2025
Quick Overview
Design a event-driven logging system that handles millions of requests. Discuss trade-offs in consistency, availability, and performance.
Twilio
August 13, 2025503
16
4,254 solved
Design a event-driven logging system that handles millions of requests. Discuss trade-offs in consistency, availability, and performance.
This is a common system design question asked during Technical Screen at Twilio. The interviewer expects you to demonstrate your ability to design large-scale distributed systems, make well-reasoned trade-offs, and communicate your thought process clearly. Twilio values engineers who can think about scalability from day one.
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
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 monitoring and alerting would you set up on day one?
- How would you handle a region-wide outage?
- 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:
- Event Ingestion: The system should accept log events from various sources (APIs, SDKs, etc.) in real-time.
- Storage: Logs should be stored persistently with m...
Capacity Estimation
To estimate capacity:
- Estimated Daily Log Events: Assume 1 million events per second (QPS) during peak hours. If we assume 12 peak hours, that leads to:
- 1 million events/second * 3600 seco...
Submit Your Answer
