DevPrep: Coding Interview

Prepare for your iOS developer interview with a plan — 5–10 minutes a day.

Hundreds of questions across 20+ topics and 1,000+ interactive challenges — the library grows regularly: Swift, SwiftUI, Swift Concurrency (async/await, actors), Combine, memory & ARC, multithreading & GCD, UIKit, Auto Layout, architecture (MVVM, VIPER, Clean), Objective-C, algorithms & data structures, networking, testing and soft skills.

WHAT'S INSIDE
• Practice: 1,000+ challenges in 9 formats — what does it print, find the bug, assemble the code, pick the fix, fill in the blank, will it crash?, estimate the complexity, select all that apply, is this API real? — with hints, explanations, Easy / Medium / Hard difficulty and a personal feed that targets your weakest topics
• AI-assisted development: review AI-generated code, spot made-up and deprecated APIs, prompts and context, theory and ready-made project rule templates — ship code with AI faster and with confidence
• iOS and AI dev news: today's highlights in short, full articles right in the app and one-tap translation
• Daily challenge and Streak widgets, Siri and Shortcuts, find articles right from iPhone search
• On-device AI on iPhones with Apple Intelligence: explain answers in your own words and get hints
• Company prep: interview stages at 24 tech companies based on public candidate reports, what candidates were asked, a day-by-day plan up to your interview date — and you can share your own questions
• Timed mock interviews, a weekly challenge, tracks and an activity calendar
• Mobile system design: 20 cases with step-by-step walkthroughs and self-checks
• Behavioral interviews: 46 questions, your own STAR stories and timed drills
• Today: what to review, what to learn next, a daily puzzle and your weak spots
• A prep roadmap for Junior, Middle and Senior — stages with must-know checklists
• Tasks from real interviews and “what does this code print” puzzles with full solutions
• Spaced-repetition trainer: missed cards come back in the same session
• Apple-docs-style answers with Swift 6 code and syntax highlighting
• A level filter across the whole library — study exactly what you need
• Progress by topic, a daily streak and goal
• Daily reminders and progress sync via iCloud
• Light and dark themes, Russian and English — switch on the fly
• Works fully offline — all content is saved on your device
• Optimized for iPhone Duo and iPad

We continuously update and expand the library of questions and tasks — new content arrives without an app update.

Basic topics and the daily challenge are free. Full access to all questions, tasks and materials unlocks with a subscription.

SUBSCRIPTION
Payment is charged to your Apple ID at confirmation of purchase. It auto-renews unless auto-renew is turned off at least 24 hours before the end of the current period. Manage your subscription in your Apple ID settings. Terms of use and the privacy policy are available in the app.