iOS Interview Questions: Get Hired As A Mobile Developer

Explore the five levels of access control in Swift: private, file private, internal, public, and open, comparing their restrictiveness and practical use in interviews.

Learn the core app delegate and scene delegate lifecycle, identify the crucial methods, and see where to place setup, pause, and cleanup code for interview-ready explanations.

Explore iOS app lifecycle with app delegate and scene delegate methods. Spot core events like will finish launching with options and discard scene sessions, noting iOS 13+ scene delegate shifts.

Learn how scene delegate methods govern the iOS app life cycle, from will connect with options to did disconnect, including initial scene setup and state restoration via info.plist.

Demonstrates iOS app and scene delegate lifecycle methods with print statements, showing the call order for launch, foreground, active, background, and termination, plus basic multi-scene configuration.

Explore the concepts of automatic reference counting in Swift, how memory is managed, and the roles of strong, weak, and unknown references, including memory leaks and detection techniques.

Learn how automatic reference counting manages memory in Swift, and how strong, weak, and unowned references prevent retain cycles and memory leaks, including closures referencing self and memory tools.

Learn how to manage memory in Swift by using strong, weak, and unowned references in closures and network calls, and fix memory leaks and retain cycles in weather data example.

Explore four common Swift iOS architectural patterns — MVC, MVP, MVVM, and VIPER — and learn interview-ready explanations of their components, pros, and trade-offs for maintainable, readable apps.

Explore the mvc architecture, where the model stores data, the view presents the user interface, and the controller coordinates updates; learn its simplicity, common use, and testing challenges.

Explore the model–view–presenter pattern, where the view handles UI, the model holds data, and the presenter manages logic, improving testability and maintainability for large iOS apps.

Explore mvvm architecture in iOS, where the view model handles logic and bindings update the model and view automatically, replacing delegation and creating smaller view controllers.

Explore VIPR architecture, separating view, interactor, presenter, entities, and router to improve maintainability and testability for large iOS apps.

Compare classes and structs, clarifying reference versus value semantics, inheritance, and extensions. Highlight when to use each, including initializers, mutating functions, and protocol conformance.

Explore the differences between structs and classes by comparing value versus reference semantics, mutating behavior, and inheritance, and learn how constants versus variables affect mutability in Swift.

Explore the features of Swift, including generics, closures, tuples, optionals, protocol extensions, memory management, and the Swift package manager, while weighing pros and cons and interview-focused comparisons to Objective-C.

Discover how the Grand Central Dispatch enables concurrency in iOS, and compare parallelism with concurrency while using dispatch queues to run tasks asynchronously or synchronously.

Explore Grand Central Dispatch concepts, distinguishing serial and concurrent queues and their task execution. Learn how main, global, and custom queues, with quality of service levels, affect UI responsiveness.

Explore gcd and concurrency in iOS: learn reader-writer problems, deadlock, and ensuring tasks finish after groups, barriers, and concurrent loops with dispatch queues and timed delays.

Explore synchronous and asynchronous tasks using GCD in Swift, learn to dispatch on global, main, or custom queues, and apply barriers, groups, and delayed execution for robust concurrency.

Explore the five iOS app states: active, inactive, background, suspended, and terminated, and learn which tasks and events occur in each for interview readiness.

Explore five iOS UI layout techniques—storyboard, nib/xib, frames, auto layout, and SwiftUI—and their pros, cons, and interview-ready guidance for selecting the right approach.