Build a multi-tenant Ad Serving Pipeline
Last updated: December 16, 2025
Quick Overview
Design a multi-tenant ad serving system that handles millions of requests. Discuss trade-offs in consistency, availability, and performance.
Coinbase
System Design
Software Engineer
Coinbase
December 16, 2025Software Engineer
System Design Round
System Design
Easy
4
5
4,868 solved
Design a multi-tenant ad serving system that handles millions of requests. Discuss trade-offs in consistency, availability, and performance.
This ML system design question from Coinbase's System Design Round tests your ability to think about ML systems at scale. The interviewer expects discussion of data quality, feature stores, model serving infrastructure, and A/B testing strategy.
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
Feature engineering and feature stores
A/B testing and experimentation
Model selection and architecture
Model serving and latency optimization
Feedback loops and model retraining
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 handle the cold start problem?
- How would you run A/B tests on different model versions?
- What would you do if model performance degrades over time?
- What is your model retraining strategy?
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:
- Multi-Tenant Support: The system must support multiple advertisers, allowing them to create, manage, and analyze their ads independently.
- Ad Serving: Serve ads...
Capacity Estimation
Back-of-Envelope Calculations:
- User Base: Assume 10 million active users.
- Ad Requests: If each user sees 10 ads per session and there are 5 sessions per day, total daily ad requests = ...
Submit Your Answer
Markdown supported