Design Netflix
PremiumProduct architectureMedium
- Video streaming
- CDN appliances
- DRM licences
Quick answer
This product architecture interview question asks you to design Netflix. Aim for a design that meets its requirements at the stated scale, then explain its main components, data flow and trade-offs. Interviewers want to see how you scope the problem, size it and defend each choice.
The problem
Design Netflix, a subscription streaming service where members browse a personalised home page, play films and series on any device and resume where they left off. The hard parts are delivering over 200 Tbps at evening peak, enforcing per-plan stream limits and keeping playback positions in sync across devices.
What must the system do?
- Home page: Each profile sees rows of titles (Continue Watching, Trending, personalised genres) with artwork, loading in under 1 second.
- Play: Pressing play starts video within 2 seconds, with quality adapting to the network and a choice of audio and subtitles.
How well must it do it?
- Peak delivery from the edge: Evening peak traffic is served mostly from CDN appliances inside ISP networks, not from the cloud origin.
- Playback survives failures: A started stream keeps playing if the home page or recommendation service fails.
What scale should you design for?
Use these numbers in your estimates.
The scale numbers unlock with this questionUnlock
Key concepts
- Video streaming
- CDN appliances
- DRM licences
- Concurrent stream limits
- Adaptive bitrate streaming
- Resume playback
How you’ll practise
- Requirements
- Core entities
- API design
- Client and server flow
- Scale and edge cases
- Wrap-up
Lala, personalized to you, gives a hint when you ask and reviews your design when you are ready.
What do interviewers look for?
In any product architecture design round.
- Clarifies the requirements before drawing anything
- Uses a few numbers that actually change the design
- Draws a clear path from the client to storage
- Picks storage and caching with reasons, not by habit
- Explains what breaks first under load and how to fix it
- States trade-offs openly instead of claiming a perfect design
Questions people ask about this interview question
- Which design type is this question?
- It is a product architecture question. You design Netflix and explain your choices the way you would in an interview.
- Is this question asked at entry level?
- It is marked Medium. Entry-level engineers can practise it, but it expects you to reason about requirements and trade-offs, not only list components.
- What should I cover first?
- Start with the requirements: what the system must do, how well it must do it and which numbers change the design. Agree on scope with the interviewer before you design anything.
- Can I practise it for free?
- It is a premium question. Sign up and unlock it once for 10 credits; it then stays unlocked. When you finish, Lala, your personalized AI mentor, can review your design for 30 credits.
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Updated · Written by the SevyDevy team