System design problems specific to mobile apps — offline-first sync, battery, location, push notifications, and platform constraints on iOS and Android.
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 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 “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 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
2 min read Waze is a fascinating mobile system design topic — millions of users producing real-time GPS pings, manual incident reports, and Read article
2 min read Mobile video conferencing is one of the most demanding mobile system design problems. The interview tests whether you can design Read article
2 min read Designing a real-time multiplayer mobile game touches more disciplines than almost any other mobile system design question — location services, Read article
2 min read “Design Google Docs mobile” is a frontier mobile system design question that combines real-time collaboration, offline editing, and rich text Read article
2 min read Mobile live streaming is fundamentally different from on-demand video. Latency matters — viewers expect their reactions to reach the streamer Read article
2 min read Apple Wallet (and Google Pay) is a mobile system design question that touches secure-element hardware, NFC protocols, payment networks, and Read article
2 min read Mobile AR is one of the most demanding mobile system design topics — combining computer vision, real-time rendering, sensor fusion, Read article
