Callback: Interview Prep

Callback prepares you for iOS developer interviews — on the train, in a waiting room, or the night before the real thing. Everything works offline. There is no account to create, nothing to sign in to, and no network connection required — only anonymous screen-view analytics on our own server. WHAT YOU GET • Eleven topics — Swift, Memory Management, Concurrency, SwiftUI, UIKit, Networking, Persistence & Data, Behavioral, Testing, Architecture & Patterns, and Mobile System Design — each with focused lessons and a bank of interview-grade questions. • Short, readable lessons with syntax-highlighted Swift, each ending in a quick check so you find out immediately whether it stuck. • Timed mock interviews with a pause-safe timer that survives backgrounding, so a phone call doesn't cost you the session. • A review queue that automatically resurfaces every question you got wrong or flagged — the fastest way to turn weak spots into strong ones. • Behavioral questions come with a model-answer rubric you score yourself against, because that's how they're actually assessed. • A readiness score that weights recent answers more heavily than old ones and accounts for how much of each topic you've actually covered. • Full VoiceOver support, Dynamic Type throughout, and Reduce Motion respected. PRIVATE BY DESIGN Your progress lives on your device and nowhere else. There is no advertising, no crash reporting, and no third-party SDK. The only thing the app sends is anonymous screen-view analytics (which screen you opened, app/OS version, device model — no identifiers) to our own self-hosted Umami server. You can export everything you've done as a JSON file, or erase it in one tap. Get the callback.