Hey Product Hunt 👋 I'm Sahitya, an Engineer. Over the last few years of interviewing at FAANG and coaching friends through Staff+ loops, I kept hitting the same problem: the good mobile system design content was either locked behind $500 courses or scattered across a dozen blog posts. So I built Mobile System Design to be the resource I wish I'd had — completely free, no signup, no paywall: • 13 deep-dive chapters (Networking → Compose → Coroutines → Offline-first) • 31 real post-mortems (Autopsy Lab) — diagnose actual Android failures from Snapchat, Instagram, Notion before reading the verdict • 25 Requirements Lab problems with a scripted interviewer that responds to your clarifying questions • 26 FAANG behavioral scenarios with IC calibration • A Code Review Lab for spotting antipatterns in broken Kotlin • Mindset Lab — see how Senior / Staff / Principal engineers think through the same scenario • Spaced repetition + a 3-min blind-spot diagnostic Everything works offline once the page loads. There's also an audio mode with 85 narrated tracks if you'd rather study on a walk. Happy to answer any questions about the interview loops I've been through, the content inside, or how I built it (Next.js 16, multi-provider AI fallback for the requirements lab). Feedback very welcome!

Mobile System Design

Android interview prep. 13 chapters, 8 labs. Free. │

Android interview prep. 13 chapters, 8 labs. Free. │