Design Spotify
PremiumProduct architectureMedium
- Audio streaming
- CDN
- Client caching
Quick answer
This product architecture interview question asks you to design Spotify. 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 Spotify, a music streaming app where people search for songs, play them instantly on any device and build playlists that stay in sync. The hard parts are starting playback in a fraction of a second from a 100-million-track catalog, merging playlist edits from several devices, and counting every play correctly for royalties.
What must the system do?
- Play: Tapping a track starts audio in under 300 ms on a good connection, and the next track in the queue starts without a gap.
- Playlists: Users create playlists of up to 10,000 tracks, add, remove and reorder tracks, and see changes on all devices within seconds.
How well must it do it?
- Instant start: Time to first audio under 300 ms at p90.
- Accurate plays: No play is lost or counted twice, including plays made offline and uploaded later.
What scale should you design for?
Use these numbers in your estimates.
The scale numbers unlock with this questionUnlock
Key concepts
- Audio streaming
- CDN
- Client caching
- Playlist sync
- Collaborative editing
- Play count events
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 Spotify 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