Design a fault-tolerant Logging System

Last updated: March 15, 2026

Quick Overview

Design a fault-tolerant logging system that handles millions of requests. Discuss trade-offs in consistency, availability, and performance.

SentinelOne
System Design
Machine Learning Engineer
SentinelOne
March 15, 2026
Machine Learning Engineer
Technical Screen
System Design
Hard

0

12

3,762 solved


Design a fault-tolerant logging system that handles millions of requests. Discuss trade-offs in consistency, availability, and performance.

System design interviews at SentinelOne 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
Message queues and async processing
Partitioning and sharding strategies
High-level architecture and component design
Database selection and data modeling
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
  • How do you ensure data consistency across multiple services?
  • How would you optimize costs as the system scales?
  • 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 Codemia
Sample Answer
Requirements

Functional Requirements:

  1. Log Ingestion: The system should accept log entries from millions of devices in real-time.
  2. Log Retrieval: Users should be able to retrieve logs based on vari...
Capacity Estimation

Assuming SentinelOne manages approximately 10 million devices worldwide, with each device generating an average of 1 log per second:

  • Total Logs per Second: 10 million logs/sec
  • **Storage Requir...

Submit Your Answer
Markdown supported

Related Questions