Design a mobile analytics SDK
PremiumMobile systemEasy
- Event batching
- Persistent event queue
- WorkManager
Quick answer
This mobile system interview question asks you to design a mobile analytics SDK. 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 a mobile analytics SDK, like the ones from Firebase or Mixpanel, that apps embed to record user events on iOS and Android. It captures events, stores them on the device and sends them in batches. The hard parts are never slowing the host app, never losing events offline and using little battery and data.
What must a mobile analytics SDK do?
- Track events: track(name, properties) and screen(name) record events with a timestamp, session ID and device context.
- User identity: identify(user_id) links later events to a signed-in user; reset() on logout starts a new anonymous ID.
How well must it do it?
- No impact on the app: track() returns in under 1 ms and never does disk or network work on the caller's thread.
- No loss, no double counting: Events survive crashes and app kills; retries never create duplicates.
What scale should you design for?
Use these numbers in your estimates.
The scale numbers unlock with this questionUnlock
Key concepts
- Event batching
- Persistent event queue
- WorkManager
- Background tasks
- Sessionization
- Consent management
How you’ll practise
- Requirements
- App architecture
- Data and offline sync
- Networking and push
- Performance, battery and releases
- 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 mobile system 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 mobile system question. You design a mobile analytics SDK and explain your choices the way you would in an interview.
- Is this question asked at entry level?
- It is marked Easy, so it suits engineers who are new to mobile system interviews. It is also a good warm-up before harder questions.
- 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