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Top 49 Swift & iOS Interview Questions & Answers (2026)

49 Questions 26 Beginner 18 Intermediate 5 Advanced

About Swift & iOS

Top 100 Swift and iOS interview questions covering Swift fundamentals, optionals, protocols, UIKit, SwiftUI, Combine, Core Data, concurrency, memory management, and app architecture. Companies hiring for Swift & iOS roles test this knowledge at every stage — from first-round screens that check the basics to final-round conversations about real-world trade-offs.

What to Expect in a Swift & iOS Interview

Expect a mix of conceptual and practical Swift & iOS questions: clear definitions and core-concept checks for junior roles, hands-on scenario questions for mid-level roles, and architecture or trade-off discussions for senior roles. Interviewers usually move from foundational topics toward the kind of problems you'd actually face on the job.

How to Use This Guide

Work through the Swift & iOS questions in order — Beginner, then Intermediate, then Advanced — so each concept builds on the last. Every question has its own page; bookmark the ones that trip you up and revisit them the day before your interview.

Curated by Tech Baithak Editorial Team · Last updated: May 2026

Beginner 26 questions

Core concepts every Swift & iOS developer must know.

01 What is Swift? 02 What are optionals in Swift? 03 What is the difference between let and var in Swift? 04 What are value types and reference types in Swift? 05 What are Swift closures? 06 What are Swift protocols? 07 What is the Swift type system — structs, classes, enums? 08 What is ARC (Automatic Reference Counting) in Swift? 09 What is UIKit? 10 What is the UIViewController lifecycle? 11 What is SwiftUI? 12 What are Swift generics? 13 What is the @State property wrapper in SwiftUI? 14 What is the difference between @ObservedObject, @StateObject, and @EnvironmentObject? 15 What are delegates in iOS? 16 What is UITableView and how do you implement it? 17 What is Auto Layout and how does it work? 18 What is a closure in Swift and how do you avoid retain cycles? 19 What is the difference between frame and bounds in UIView? 20 What is Grand Central Dispatch (GCD)? 21 What is Core Data in iOS? 22 What is Combine in Swift? 23 What is Swift error handling? 24 What are Swift access control levels? 25 What is the iOS app lifecycle? 26 What is the MVVM architecture pattern in iOS?

Intermediate 18 questions

Practical knowledge for developers with hands-on experience.

01 What is Swift concurrency (async/await)? 02 What are Swift actors? 03 What is the Coordinator pattern in iOS? 04 What is NSURLSession and networking in iOS? 05 What is UserDefaults and when should you use it? 06 What is the Keychain and when do you use it? 07 What is dependency injection in Swift/iOS? 08 What is the difference between synchronous and asynchronous operations in iOS? 09 What is UICollectionView? 10 What is Codable in Swift? 11 What are property wrappers in Swift? 12 What is the difference between frame-based and Auto Layout? 13 What is WKWebView and how does it differ from UIWebView? 14 What is push notifications and APNs in iOS? 15 What is the difference between nil coalescing and optional chaining? 16 What is SwiftUI's NavigationStack? 17 What is Core Location in iOS? 18 What is memory management in Swift collections?

Advanced 5 questions

Deep expertise questions for senior and lead roles.

01 What is Swift's type system — protocols with associated types and existentials? 02 What is Swift's concurrency model — Sendable and actor isolation? 03 What are Swift macros? 04 What is SwiftData? 05 How do you optimize iOS app performance?

Back to All Topics 49 questions total