Mobile System Design

⏱ 2 min read The Uber driver app is a different beast from the rider app. It runs all day, must survive on cellular, […] Read article

⏱ 2 min read Voice assistants (Siri, Google Assistant, Alexa) are deceptively complex mobile system design topics. Always-listening for a wake word, on-device automatic Read article

⏱ 3 min read Deep linking — the ability to open a specific screen in your app from a URL — is fundamental to Read article

⏱ 2 min read Onboarding is one of the highest-leverage UI flows. Every percentage point of drop-off is real users who never become customers. Read article

⏱ 2 min read Designing a Kindle-style mobile reading app is a layered system design problem. Format rendering, position sync across devices, offline downloads, Read article

⏱ 2 min read Mobile news apps (Apple News, Google News, Flipboard, NYT app) sit at an unusual intersection of feed personalization, time-sensitive push Read article

⏱ 2 min read Modern mobile translation apps (Google Translate, Apple Translate) increasingly run inference on-device. The interview tests whether you understand the tradeoffs Read article

⏱ 2 min read Live audio rooms (Clubhouse, Twitter Spaces, Discord Stage Channels) are an interesting mobile system design topic. They sit between video Read article

⏱ 2 min read QR scanners are a deceptively rich mobile system design problem. Camera capture in real time, edge case handling (low light, Read article

⏱ 2 min read Smart home apps (Apple Home, Google Home, SmartThings, Hue) sit at an unusual intersection of mobile development, IoT, network protocols, Read article

⏱ 2 min read “Design a file sync system on mobile” is a classic system design topic that gets harder as you dig in. Read article

⏱ 2 min read Designing a mobile wearable companion app like an Apple Watch app or Wear OS counterpart is a multi-device system design Read article

⏱ 2 min read Designing a mobile podcast app is a deceptively rich system design exercise. Audio streaming with prefetch, offline downloads with smart Read article

⏱ 2 min read A mobile authenticator app is a small surface with disproportionately strict requirements. The user trusts it with the second factor Read article

⏱ 3 min read Mobile health apps work with sensitive personal data — heart rate, sleep, steps, weight. The interview tests whether you understand Read article