System Design

⏱ 3 min read “Design a smart home app” is a senior+ mobile system design that combines protocol heterogeneity, real-time control, automations, and the […] Read article

⏱ 3 min read “Design a voice memos app” looks like a simple recorder until you list the requirements: high-quality audio capture, on-device transcription, Read article

⏱ 3 min read “Design a dating app” varies by which app you mean. Tinder is swipe-based; Hinge is profile-comment-based; Bumble is conversation-window-based. This Read article

⏱ 3 min read “Design Lime / Bird / Citi Bike” is a senior+ mobile system design that combines geographic discovery, IoT unlock-and-lock, real-time Read article

⏱ 3 min read “Design Ticketmaster” or “design an event ticketing app” is a senior+ mobile system design prompt that combines extreme load spikes Read article

⏱ 3 min read “Design a kids’ educational app” is a regulated-industry mobile system design — Khan Academy Kids, Duolingo ABC, ABCmouse, Lingokids, Yousician Read article

⏱ 3 min read “Design a sky map app” is a sensor-and-AR mobile system design prompt — Sky Guide, SkySafari, Stellarium, Star Walk are Read article

⏱ 3 min read “Design Webtoon” or “design a comics reader” is a content-and-rendering mobile system design — Webtoon, ComiXology, Crunchyroll Manga, Manga Plus, Read article

⏱ 3 min read “Design Mint” is a fintech-flavored mobile system design prompt that combines bank-data aggregation, transaction categorization, budgeting UX, and the strict Read article

⏱ 3 min read “Design a fitness coaching app” is the structured-workout cousin of the Strava-style activity-tracking question. Peloton App, Nike Training Club, Apple Read article

⏱ 2 min read “Design an online course app” is a content-and-progress mobile system design prompt — Coursera, Udemy, Khan Academy, Duolingo, Brilliant. The Read article

⏱ 3 min read “Design a translation camera” is a vision-and-AR mobile system design prompt — Google Lens / Translate, Apple’s Live Text + Read article

⏱ 3 min read “Design Signal” or “design an E2E messenger” is a senior+ mobile-system-design prompt that probes whether you understand modern cryptography, multi-device Read article

⏱ 3 min read “Design a transit app” is a niche but technically rich mobile-system-design prompt. Citymapper, Transit, Moovit, Apple Maps Transit are the Read article

⏱ 3 min read “Design a travel booking app” combines search at scale, payment, complex itinerary management, and the unforgiving UX of “I am Read article