Intermediate interview questions in Mobile Dev, page 6
Redux versus Zustand state management
Redux uses actions, reducers, and a Provider with structured boilerplate; Zustand offers a minimal hook-based store with no provider and selective subscriptions.
Pass data back from a modally presented view controller delegate versus closure
This tests decoupled UIKit communication and memory safety. A strong answer outlines a weak delegate protocol and a closure with weak self, contrasting coupling and retain cycles. Red flag: singletons or direct parent references.
Difference between Style and Theme, and how ?attr/ resolves vs @color/
Probes Android resource indirection depth. A style targets one View; a theme targets a Context. ?attr/ resolves dynamically against the current theme at runtime, but @color/ is a static compile-time constant. Red flag: saying both resolve the same way.
Android Style vs. Theme and Attribute Resolution
Tests your grasp of Android's resource scope and resolution timing. A Style targets a single View, while a Theme applies to a whole Context. @color/ is a direct, compile-time link; ?attr/ is an indirect pointer resolved against the Theme at runtime.
Styles vs. Themes and Attribute Resolution in Android
This tests your grasp of Android's resource indirection. A Style is a set of attributes for one View type. A Theme is a collection of named attributes for an app or Activity. ?attr is resolved at runtime against the Theme, while @color is a direct.
Handle a deep link URL in SceneDelegate and navigate to order detail.
Handles willConnectTo and openURLContexts; parses path with URLComponents; validates ID; pushes detail onto nav stack.
How does ConstraintLayout enable flat responsive UIs with chains and barriers?
It tests constraint-based positioning and flat hierarchy performance. A strong answer covers relative constraints replacing nested layouts, chains for distributing groups, and barriers for dynamic alignment to extreme edges.
Explain ConstraintLayout, Chains, and Barriers
Tests your grasp of performant Android UIs. Explain how ConstraintLayout flattens hierarchy, use chains to distribute groups of views (e.g., packed), and use barriers to align elements against dynamic content.
How does ConstraintLayout enable complex, responsive UIs?
Tests your grasp of modern Android UI performance and responsiveness. Explain how relative positioning flattens hierarchies, then define chains for distributing space and barriers for handling dynamic content size.
How do you pop to root in SwiftUI NavigationStack?
This tests declarative state-driven navigation. A strong answer binds NavigationStack to a NavigationPath, passes the binding down, and clears the path to pop to root. A red flag is suggesting UIKit popToRootViewController or legacy isActive hacks.
Build and validate a login form with Form and GlobalKey
This tests Flutter's declarative form validation. A strong answer covers wrapping fields in a Form, using a GlobalKey<FormState>, calling validate on submit, and acting only on true.
What is a FocusNode and why is it useful in forms?
This tests your understanding of Flutter's imperative focus tree. A strong answer defines FocusNode as a persistent focus target, explains programmatic form navigation, and stresses initState creation and dispose.
What gesture conflict exists in a scrollable list with horizontal swipes?
Tests Flutter's gesture arena and slop disambiguation. Diagonal motion triggers both vertical scroll and horizontal swipe; the axis whose delta exceeds touch slop first wins the arena. Red flag: claiming Flutter blocks inner gestures or fires both at once.
Explain Jetpack Compose recomposition, its triggers, and optimizations.
This tests grasp of Compose's reactive model. A strong answer defines recomposition as recomputing composables when state changes, notes State triggers it, and explains Compose skips unchanged subtrees via smart tracking.
Explain Recomposition in Jetpack Compose
This tests your core understanding of Compose's declarative model. Explain that recomposition is re-running composables when state they read changes. Mention that Compose optimizes by only recomposing the nearest scope and skipping composables with stable…
Explain Recomposition in Jetpack Compose
Tests your grasp of Compose's declarative model. A good answer defines recomposition, explains state-read triggers, and details how stability and positional memoization enable skipping. A red flag is assuming any state change redraws the entire UI.
Robust network error handling strategy
Classify errors as 4xx, 5xx, or connectivity; retry transient failures with backoff, surface actionable messages, and check NetInfo.
Describe state hoisting and its benefits in Compose
Move state to the caller, pass value and event lambda down, keep them stateless.
Describe the state hoisting pattern in Compose
Tests your grasp of unidirectional data flow. Explain state hoisting is moving state up to make composables stateless. This enables reusability, easier testing, and a single source of truth. A red flag is just describing the mechanics without the benefits.
Describe state hoisting in Jetpack Compose.
Tests your grasp of unidirectional data flow. Explain state hoisting is moving state up to make composables stateless. This improves reusability, testability, and creates a single source of truth. A red flag is defining it without explaining the benefits.
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