Kotlin Coroutines and Flow for Android Development [2026]

Explore approaches to asynchronous programming, compare callbacks, RxJava, and Kotlin coroutines, weigh the benefits and drawbacks, and see why Kotlin coroutines are the current best approach for Android.

Implement Kotlin coroutines in the ViewModel to perform sequential network requests with suspend functions and Retrofit, using the ViewModel scope and launch, while handling loading state and errors.

Explore how Kotlin coroutines simplify asynchronous programming for Android development, offering comprehensible, imperative-style code with familiar constructs, high flexibility, and first-class support from Google and JetBrains.

Master the basics and theory of Kotlin Coroutines, comparing them to regular routines, exploring suspend functions, non-blocking behavior, and the Coroutines library source code behind delay.

Explore the difference between routines and coroutines by comparing ordinary functions with suspend functions and delay, and see how cooperative coroutines share control flow.

Explore suspend functions in Kotlin coroutines, learn how they perform long running operations without blocking threads, how to call them from coroutines or async blocks, and recognize suspension points.

Highlight blocking and suspending in Kotlin coroutines by showing how Thread.sleep blocks threads, while delay suspends without blocking the main thread.

Explore multithreaded coroutines, switch threads with withContext and default dispatcher, and offload blocking calls to background threads to prevent UI freezing.

Recap the core concepts of Kotlin coroutines and Android dependencies, including suspend functions, launch and async, main safety, Retrofit usage, and basic error handling with try-catch.

Implement use case #3 by sequentially loading Android version features with a ViewModel and loading indicator, then optimize by performing network requests concurrently using async in coroutines.

Implement a sequential use case that fetches recent Android versions from the Android versions endpoint and loads each version's features via sequential network requests, illustrating Kotlin coroutines and map operator.

Implement use case four concurrently to run Android version feature requests in parallel, reducing total network time from about 4000 ms to about 2000 ms using Kotlin coroutines.

Demonstrates launching a ViewModel-scoped coroutine, using async and awaitAll to fetch Android version features in parallel, reducing load time from four to two seconds and updating the UI.

Learn to implement timeouts and retries for network requests using Kotlin coroutines, via with timeout and with timeout or null, including UI input and timeout handling.

Learn to implement retry logic for network requests in Kotlin coroutines using repeat, with two retries, and error handling via try-catch and Timber in loadRecentAndroidVersions with a mock api.

Add exponential backoff to the retry function by introducing initial delay, max delay, and a doubling factor, using a suspend delay between retries.

Perform two parallel network requests for Android Oreo API 27 and Pie API 28 features. Use timeout and optional retries, combining these concepts to display the data in the UI.

Demonstrate a retry-with-timeout solution using coroutines, running parallel fetches for Android version features, handling timeouts and retries toward a successful response.

Implement a room database cache to load Android versions from database or network, update the UI with status icons, and provide a clear database option.

Connect your app to a room database using suspend functions in data access objects to store and load data, leveraging Android Jetpack and coroutine support with libraries like WorkManager.

Learn to use coroutines to perform background operations, switch between contexts, and choose dispatchers to keep your app responsive.

Learn to implement a factorial calculation in a background coroutine inside a ViewModel, measure computation and string conversion durations, and update the UI with a success state.

Understand how the coroutine context governs execution by detailing dispatchers, the job, and the error handler within the ViewModel scope, including main, a background dispatcher, and structured concurrency.

Explore the main, IO, and default coroutine dispatchers for Android, and learn when to use each, including creating custom dispatchers with new single thread context.

Explains how to use withContext for safe context switching in coroutines, moving CPU-heavy work to the default dispatcher and returning to the main thread to update the UI without freezing.

Distribute factorial calculation across multiple coroutines by dividing into subranges and running them in parallel, then multiply subresults to obtain factorial and convert result on a background thread.

Implement a parallel factorial calculator with Kotlin coroutines, using withContext to switch to the default dispatcher, async subrange tasks, awaitAll, and fold to the final result.

Master structured concurrency to cancel coroutines when users leave the screen and handle partial network failures without crashing.

Explore structured concurrency in Kotlin coroutines by starting coroutines in a logical scope, forming parent-child hierarchies, and handling cancellations and exceptions to prevent resource waste in Android apps.

Explore structured concurrency by creating a scope in Android Studio, launching coroutines, and canceling the scope to end the lifetime of child jobs.

Explore how coroutines form a hierarchy within a scope by creating and linking jobs, launching child coroutines, and understanding how context elements shape the parent child relationship in structured concurrency.

Explore Kotlin coroutines and Flow by seeing how a parent job waits for all child coroutines to finish, using join, runBlocking, and delays to demonstrate task completion.

Learn how structured concurrency handles cancellation: cancel a parent to cancel all children, while canceling a single child won’t affect its parent or siblings, using the cancel and join function.

Explore exception propagation and job hierarchy in Kotlin coroutines, comparing ordinary jobs and supervisor jobs. Ordinary jobs cancel siblings and the scope on failure; supervisor jobs do not.

Avoid the global scope to prevent unbounded lifetimes of top level coroutines and rely on lifecycle scopes like ViewModel for automatic cancellation.

Launch coroutines in the ViewModel scope to fetch the recent Android versions from a mock API, and cancel them when the ViewModel is cleared, using a supervisor job and dispatchers.main.immediate.

Explore scoping functions for parallel decomposition using coroutineScope and supervisorScope, installing child coroutines with proper cancellation behavior. Learn when to use coroutineScope for cascading cancellations and supervisorScope for independent tasks.

Explore how Kotlin coroutines handle cancellation, using a sample that launches a coroutine, delays, and is canceled, showing cancellation exceptions and cooperative cancellation across suspend functions.

Use withContext with the non-cancellable job to run cleanup code after cancellation, allowing suspend calls like delay and preventing cancellation exceptions during a critical section.

Demonstrates making a factorial calculation cooperative with cancellation in a ViewModel by introducing a calculation job, a cancel button, and using yield to periodically check activity, preventing memory leaks.

Master cooperative cancellation in Kotlin coroutines by using ensureActive or yield, checking isActive in custom suspend functions, and guarding cleanup with context and a non-cancellable job.