Build a real-time Video Streaming Pipeline
Last updated: January 27, 2026
Quick Overview
Design a real-time video streaming system that handles millions of requests. Discuss trade-offs in consistency, availability, and performance.
Brex
January 27, 202610
7
1,864 solved
Design a real-time video streaming system that handles millions of requests. Discuss trade-offs in consistency, availability, and performance.
ML system design at Brex goes beyond model selection. This System Design Round question evaluates your ability to design end-to-end ML pipelines, from data collection to model serving, while considering production constraints like latency and reliability.
What the Interviewer Expects
- Define clear ML objectives with appropriate loss functions and metrics
- Design a comprehensive feature engineering pipeline
- Discuss model selection with trade-offs (complexity vs interpretability vs latency)
- Plan online and offline evaluation strategies including A/B testing
- Address serving infrastructure: batch vs real-time, latency requirements
- Consider data quality, labeling strategy, and feedback loops
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
- How would you handle the cold start problem?
- How would you debug a model that works well offline but poorly online?
- What is your model retraining strategy?
- How would you ensure fairness and reduce bias in the model?
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:
- Support real-time video streaming with minimal latency (target < 300ms).
- Handle millions of concurrent users with seamless scaling.
- Provide adaptive...
Capacity Estimation
Assuming Brex anticipates 10 million concurrent streams at peak usage:
- Average Stream Duration: 30 minutes.
- Total Sessions per Hour: 10 million streams * 2 (for 2 streams per hour) =...
Submit Your Answer
