Android System Design Interview Practice Questions & Preparation Guide

System design rounds are becoming common, even for mobile engineers. This guide will serve as a list of questions you should definitely do before your interview.

You should practice these questions on Mockingly.AI for best experience and mocks. Many of these questions are sourced from mockingly.

Preparation Strategy

System design interviews are about discussions. More than anything else, you should think out loud. Treat this as a discussion, take the lead and direct the interview as you like.

Here's some tips for preparation:

1. Read: First things first, if you're new to this, read how and what's discussed in android system design interviews. Read the question and the solution both and see how interview progresses.
2. Know your basics: You should know your basics like how do http, websockets, graphql, REST work, app lifecycle, launch modes, http vs https, nosql vs sql database in android, recyclerview and optimisation, diffutils. These are basically trivias which can be asked in the interview and it really helps knowing the depths of these.
3. Know how to start: I used to freeze up seeing a design question as I didn't know how to start. So set your starting ritual. What would you ask the interviewer ? eg. clarify about functional vs non-functional requirements, audience size and location, offline support etc... In Android, it's also important to know which component to draw first. I tend to start with a screen and it's viewmodel, you can have your own way to start.
4. Mocks: Practicing mock interviews for android system design is absolutely necessary. You can do this on mockingly, it's pro version is cheap and unlocks a list of company questions that'll be helpful. It's affordable compared to other mock interview solutions.
5. Signals: Provide signals. Signals as in hints to the interviewer that you know what you're talking about. Talk about Pagination so they know you care about performance, talk about avoiding memory leaks, talk about battery performance, even if the interviewer hasn't asked for it. But be careful to only talk about the stuff you know about as interviewer might grill you on this.

Android System Design Practice Questions

1. Design a Chat Application which supports multi-media messages (image, video), read receipts and group chats: Practice this on mockingly
2. Design a Networking Library
3. Design a photo editing app: (In this question you can begin by clarifying the type of edits to support).
4. File uploading library
5. Design an image loading library: (You should ask about the type of "targets" to support, like imageview, sdcard, cache, and about the scaling options). Practice this on mockingly
6. Generic mobile caching library to support caching data.
7. Design Uber's mobile app.
8. Design Shopping Cart page for an e-commerce app. Useful for e-commerce company's interviews. You should think about things like cart abandonment, checkout process and how checkout works.
9. Design an App Store (or Google Play Store). A version of this could be: design an app store for internal employees.
10. Design a flight booking application: Think about how will you store data offline so that user can access their boarding pass even without network.
11. Design spotify/music streaming application. Think about what protocols you could use.
12. Design a price ticker application which shows prices for stocks/cryptos. (think about what will you use among REST, GQL, WebSockets, gRPC etc...)
13. Design Instagram and include the Stories feature.
14. Design Smart Home Control mobile app. Practice this on mockingly
15. Calendar app with events sync. Practice this on mockingly
16. Android system design for QR Code scanning app. Practice this on mockingly
17. Password manager app. Practice this on [mockingly]
18. ...I'll keep updating this list as I find more questions to add in the list.

Company Specific System Design Questions

You can try solving company specific questions on Mockingly which has a curated list of questions asked previously in actual interviews.

These are not bulk questions but carefully crafted after making sure that they were asked in the interviews. It also includes a solution to those questions, but you should try solving them yourself or finding solutions online.

Hope this works for you. I'll keep updating this list with questions whenever I find some :)