Architect a low-latency URL Shortening Engine

Last updated: March 20, 2026

Quick Overview

Design a low-latency url shortening system that handles millions of requests. Discuss trade-offs in consistency, availability, and performance.

Stripe
System Design
Software Engineer
Stripe
March 20, 2026
Software Engineer
Technical Screen
System Design
Easy

10

7

1,317 solved


Design a low-latency url shortening system that handles millions of requests. Discuss trade-offs in consistency, availability, and performance.

Stripe asks this during the Technical Screen to assess your understanding of the full ML lifecycle. They want to see how you translate a business problem into an ML objective, design the feature pipeline, and plan for model monitoring and retraining.

What the Interviewer Expects
  • Map the business problem to a concrete ML objective
  • Propose reasonable features and a baseline model
  • Discuss basic model evaluation metrics
  • Outline a simple serving architecture
Key Topics to Cover
Feedback loops and model retraining
Online vs offline evaluation
Model selection and architecture
Data collection and labeling strategy
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 would you run A/B tests on different model versions?
  • How would you ensure fairness and reduce bias in the model?
  • How would you handle a 10x increase in prediction requests?
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 low-latency URL Shortening Engine, key functional requirements includ...

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