⏱ 3 min read The Tinder swipe deck is a fascinating UX-engineering challenge. Cards must be prefetched so swiping never hits a network spinner. […] Read article

⏱ 2 min read Designing a fitness tracker like Strava is a great mobile system design question because it combines hardware (GPS, accelerometer, heart Read article

⏱ 3 min read “Design Robinhood” is a deceptively hard mobile system design question. The interviewer wants to see if you can handle real-time Read article

⏱ 3 min read Slack on mobile is harder than chat. Chat apps have one thread per conversation. Slack has channels with threads inside Read article

⏱ 3 min read “Design Spotify mobile” is a layered question. The basic streaming case is straightforward — fetch a manifest, download audio, play. Read article

⏱ 3 min read Push notifications look simple from the user side — a banner appears, you tap it, the app opens. From an Read article

⏱ 3 min read “Design a mobile app that works fully offline” is a common system design prompt. Real-world examples: notes apps, todo apps, Read article

⏱ 3 min read TikTok’s mobile feed is one of the hardest moving targets in mobile engineering. Vertical full-screen video, instant-tap scroll, autoplay with Read article

⏱ 3 min read “Design Uber” usually means the dispatcher backend. In a mobile system design round you are designing the rider experience: a Read article

⏱ 4 min read Designing Instagram in a mobile interview is different from designing it as a backend system. The interviewer wants to see Read article

⏱ 2 min read “Design WhatsApp” sounds like a backend question, but in a mobile system design round the interviewer wants to see you Read article