# Android Testing Advanced (Android) > Advanced Android testing: TDD, mocking, Coroutines, Flow, Compose UI, and test coverage - 18 interview questions - Senior - [Interview Questions: Android](https://sharpskill.dev/en/technologies/android/interview-questions.md) ## 1. How do Mock, Stub, and Fake differ in tests? **Answer** A Mock verifies interactions (who calls what, how many times, with which arguments). A Stub returns predefined responses without verification. A Fake is a simplified working implementation (e.g., in‑memory repository). Mocks emphasize behavior verification, Stubs support state verification, and Fakes provide lightweight realistic alternatives. ## 2. How to use MockK for mocking in Kotlin? **Answer** MockK is Kotlin‑centric: mockk() creates a double, every { ... } returns ... stubs responses, verify { ... } checks interactions. It supports coroutines (coEvery/coVerify), relaxed mocks, and argument capture via slot. ## 3. What is TDD (Test-Driven Development)? **Answer** TDD means writing a test before the code and iterating Red‑Green‑Refactor: failing test, minimal code to pass, then refactor without changing behavior. Benefits: better coverage, more testable design, living documentation. ## 15 more questions available - How to test Coroutines with runTest? - How to test Flow? Sign up for free: https://sharpskill.dev/en/login ## Other Android interview topics - [Android Fundamentals](https://sharpskill.dev/en/technologies/android/interview-questions/android-fundamentals.md): 24 questions, Junior - [Android UI and Resources](https://sharpskill.dev/en/technologies/android/interview-questions/android-ui-and-resources.md): 30 questions, Junior - [Android Lifecycle](https://sharpskill.dev/en/technologies/android/interview-questions/android-lifecycle.md): 30 questions, Junior - [Android Navigation](https://sharpskill.dev/en/technologies/android/interview-questions/android-navigation.md): 26 questions, Junior - [Android Data Management](https://sharpskill.dev/en/technologies/android/interview-questions/android-data-management.md): 29 questions, Junior - [Android Networking](https://sharpskill.dev/en/technologies/android/interview-questions/android-networking.md): 29 questions, Junior - [Android Testing](https://sharpskill.dev/en/technologies/android/interview-questions/android-testing.md): 28 questions, Junior - [Android Gradle](https://sharpskill.dev/en/technologies/android/interview-questions/android-gradle.md): 26 questions, Junior - [Kotlin Language Essentials for Android](https://sharpskill.dev/en/technologies/android/interview-questions/android-kotlin-language-essentials.md): 24 questions, Junior - [Room Database](https://sharpskill.dev/en/technologies/android/interview-questions/android-room-database.md): 25 questions, Mid-Level - [Background Work](https://sharpskill.dev/en/technologies/android/interview-questions/android-background-work.md): 18 questions, Mid-Level - [Jetpack Compose](https://sharpskill.dev/en/technologies/android/interview-questions/android-compose.md): 28 questions, Mid-Level - [Permissions and Device Features](https://sharpskill.dev/en/technologies/android/interview-questions/android-permissions-and-device.md): 21 questions, Mid-Level - [Firebase for Android](https://sharpskill.dev/en/technologies/android/interview-questions/android-firebase.md): 23 questions, Mid-Level - [Android MVVM Architecture](https://sharpskill.dev/en/technologies/android/interview-questions/android-mvvm-architecture.md): 18 questions, Mid-Level - [Advanced Android Networking](https://sharpskill.dev/en/technologies/android/interview-questions/android-networking-advanced.md): 13 questions, Mid-Level - [Kotlin Collections and Operators](https://sharpskill.dev/en/technologies/android/interview-questions/android-kotlin-collections-operators.md): 20 questions, Mid-Level - [Kotlin Coroutines and Flow](https://sharpskill.dev/en/technologies/android/interview-questions/android-kotlin-coroutines-flow.md): 20 questions, Mid-Level - [Android Dependency Injection](https://sharpskill.dev/en/technologies/android/interview-questions/android-dependency-injection.md): 15 questions, Mid-Level - [Android MVI Architecture](https://sharpskill.dev/en/technologies/android/interview-questions/android-mvi-architecture.md): 17 questions, Mid-Level - [Android Clean Architecture](https://sharpskill.dev/en/technologies/android/interview-questions/android-clean-architecture.md): 21 questions, Senior - [Android Compose Advanced](https://sharpskill.dev/en/technologies/android/interview-questions/android-compose-advanced.md): 17 questions, Senior - [Android Performance and Monitoring](https://sharpskill.dev/en/technologies/android/interview-questions/android-performance-monitoring.md): 13 questions, Senior - [Android Security and Privacy](https://sharpskill.dev/en/technologies/android/interview-questions/android-security-privacy.md): 18 questions, Senior - [Android CI/CD and Release](https://sharpskill.dev/en/technologies/android/interview-questions/android-cicd-release.md): 15 questions, Senior - [Android UX and Form Factors](https://sharpskill.dev/en/technologies/android/interview-questions/android-ux-form-factors.md): 18 questions, Senior --- Source: SharpSkill (https://sharpskill.dev), tech interview preparation for your real stack. 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