Kotlin Coroutines: Common Mistakes and Fixes

🚫 5 𝗞𝗼𝘁𝗹𝗶𝗻 𝗖𝗼𝗿𝗼𝘂𝘁𝗶𝗻𝗲 𝗠𝗶𝘀𝘁𝗮𝗸𝗲𝘀 𝗘𝘃𝗲𝗿𝘆 𝗔𝗻𝗱𝗿𝗼𝗶𝗱 𝗗𝗲𝘃𝗲𝗹𝗼𝗽𝗲𝗿 𝗦𝗵𝗼𝘂𝗹𝗱 𝗔𝘃𝗼𝗶𝗱 ❌ Kotlin Coroutines are powerful, but using them incorrectly can lead to 𝗺𝗲𝗺𝗼𝗿𝘆 𝗹𝗲𝗮𝗸𝘀, 𝗰𝗿𝗮𝘀𝗵𝗲𝘀, 𝗼𝗿 𝗳𝗿𝗼𝘇𝗲𝗻 𝗨𝗜𝘀. Here are the top 5 mistakes: 1️⃣ 𝗨𝘀𝗶𝗻𝗴 𝗚𝗹𝗼𝗯𝗮𝗹𝗦𝗰𝗼𝗽𝗲 𝗰𝗮𝗿𝗲𝗹𝗲𝘀𝘀𝗹𝘆 𝘎𝘭𝘰𝘣𝘢𝘭𝘚𝘤𝘰𝘱𝘦 coroutines live as long as the app. If you launch long-running tasks in 𝘎𝘭𝘰𝘣𝘢𝘭𝘚𝘤𝘰𝘱𝘦, they won’t automatically cancel when your activity or fragment is destroyed. 2️⃣ 𝗕𝗹𝗼𝗰𝗸𝗶𝗻𝗴 𝘁𝗵𝗲 𝗠𝗮𝗶𝗻 𝗧𝗵𝗿𝗲𝗮𝗱 Blocking the main thread with 𝘳𝘶𝘯𝘉𝘭𝘰𝘤𝘬𝘪𝘯𝘨 or heavy computation freezes the UI. Coroutines should run asynchronously on the proper dispatcher. 3️⃣ 𝗜𝗴𝗻𝗼𝗿𝗶𝗻𝗴 𝗲𝘅𝗰𝗲𝗽𝘁𝗶𝗼𝗻𝘀 Exceptions in coroutines can fail silently or crash your app if not handled properly. Always catch exceptions or use a 𝘊𝘰𝘳𝘰𝘶𝘵𝘪𝘯𝘦𝘌𝘹𝘤𝘦𝘱𝘵𝘪𝘰𝘯𝘏𝘢𝘯𝘥𝘭𝘦𝘳. 4️⃣ 𝗡𝗼𝘁 𝗰𝗮𝗻𝗰𝗲𝗹𝗹𝗶𝗻𝗴 𝗷𝗼𝗯𝘀 Long-running coroutines that are never cancelled can cause memory leaks. Always cancel coroutines when the corresponding lifecycle ends. 5️⃣ 𝗠𝗶𝘅𝗶𝗻𝗴 𝗗𝗶𝘀𝗽𝗮𝘁𝗰𝗵𝗲𝗿𝘀 𝗶𝗻𝗰𝗼𝗿𝗿𝗲𝗰𝘁𝗹𝘆 CPU-heavy tasks on 𝘋𝘪𝘴𝘱𝘢𝘵𝘤𝘩𝘦𝘳𝘴.𝘔𝘢𝘪𝘯 or UI tasks on 𝘋𝘪𝘴𝘱𝘢𝘵𝘤𝘩𝘦𝘳𝘴.𝘐𝘖 can freeze the UI or block background threads. Always choose the correct dispatcher. 💡 𝗣𝗿𝗼 𝗧𝗶𝗽: Combine 𝗹𝗶𝗳𝗲𝗰𝘆𝗰𝗹𝗲-𝗮𝘄𝗮𝗿𝗲 𝘀𝗰𝗼𝗽𝗲𝘀, 𝗰𝗼𝗿𝗿𝗲𝗰𝘁 𝗱𝗶𝘀𝗽𝗮𝘁𝗰𝗵𝗲𝗿𝘀, and 𝗲𝘅𝗰𝗲𝗽𝘁𝗶𝗼𝗻 𝗵𝗮𝗻𝗱𝗹𝗶𝗻𝗴 to make coroutines safe, efficient, and maintainable. #Kotlin #AndroidDev #Coroutines #MobileDevelopment #BestPractices #Programming #SoftwareEngineering #AppDevelopment #AndroidKotlin #CleanCode #DevTips #AndroidStudio #AsyncProgramming #Jetpack #MVVM #CodingTips

✍️ Coroutines vs Threads in Android – What’s the Real Difference? When building Android apps, we often face a common question: 👉 Should I use Threads or Coroutines for background tasks? Let’s break it down simply 👇 🔲 Thread ▪️A Thread is a low-level OS concept. ▪️Each Thread has its own memory stack, which means it’s heavy in terms of system resources. ▪️Creating too many threads can easily lead to OutOfMemoryErrors or performance issues. ▪️Once started, it runs until completion — managing and canceling them isn’t very flexible. 🔲 Coroutine ▪️A Coroutine is a lightweight thread managed by the Kotlin runtime, not the OS. ▪️They can be suspended and resumed without blocking threads, making them perfect for async tasks like API calls, database queries, or background I/O. ▪️Thousands of coroutines can run on a handful of threads thanks to structured concurrency. ▪️Easier cancellation, error handling, and clean lifecycle management (especially with viewModelScope, lifecycleScope). 💡 In short: Threads are heavy and managed by the system. Coroutines are light and managed by Kotlin. 🧠 Pro tip: Always prefer Coroutines for modern Android development — they make async programming cleaner, safer, and more efficient. #AndroidDevelopment #Kotlin #Coroutines #Multithreading #MobileDevelopment #Programming #SoftwareEngineering

New on Medium: How to Build a Robust SMS OTP Retrieval System in Android You know that moment when you’re waiting for an OTP… and it finally arrives — but the app session has expired? Yeah, that. 😅 I decided to fix that once and for all. In this new post, I break down how to build a secure, modern, and user-friendly OTP retrieval system using the SMS User Consent API — no READ_SMS permission drama, no messy broadcast chaos. Here’s what you’ll learn: 1. Setting up the Consent API properly 2. Building a clean utility class for reusability 3. Integrating it seamlessly into fragments 4. Handling edge cases like a pro 💡 Bonus: it’s written in Kotlin, explained like we’re pair programming over coffee ☕ If you’re an Android dev looking to make OTP verification buttery smooth for your users (and your sanity), check it out 👇 🔗 Read it here on Medium: https://lnkd.in/gTYHSVQ9 #Android #Kotlin #CleanArchitecture #SMSUserConsent #DeveloperLife #TechHumor #AndroidDevelopers #MobileEngineering #RaenestEngineers

Most Android devs handle Kotlin Coroutine exceptions wrong. Even seasoned engineers make these 5 mistakes 1. Wrapping launch in try/catch (it never catches) 2. Expecting CoroutineExceptionHandler to fix everything 3. Using async for fire-and-forget jobs 4. Swallowing CancellationException 5. Forgetting supervisorScope — one crash kills all Pro tip: Always catch inside your coroutine, rethrow cancellations, and isolate jobs with supervisorScope. I broke down 15 real-world mistakes + production-safe fixes here Read the full guide https://lnkd.in/gRD9xhPu #KotlinCoroutines #KotlinDevelopers #AndroidDevelopment #StructuredConcurrency #AsyncProgramming #CleanCode #ErrorHandling #AndroidEngineering #SoftwareCraftsmanship #KotlinTips #ViewModelScope #MobileDevelopment #AndroidDev #CoroutineBestPractices #ProductionReadyCode

Improving #Productivity In Android Two #Android #developers, #Sarah and #Mark, are at their desks. Mark is reviewing a #pull #request. #Mark: "Hey Sarah, I'm looking at your PR. The core logic is perfect, but I've left about a dozen comments on small things—#wildcard #imports, a few magic numbers, and some line-length #violations." #Sarah: "Oh, sorry about that. I'll work through them now. I really thought I had caught all of those." #Mark: "No worries, it happens to everyone. It just adds a bit of back-and-forth to the review process. But check this out—if we use #Detekt and define our #rules, it will catch all these minor violations automatically right in the PR." #Sarah: "That would be a huge win! It's like the check would pass on its own, making our code cleaner without even feeling like extra work." #Mark: "Exactly. Definitely less time spent on manual nitpicks in reviews, and more time for the actual logic." Hi, you must have crossed your path something like this definitely, so I thought to write a blog on how to implement this properly using #buildSrc Kotlin DSL! #Android #Dev #Developer #kotlin #java #dsl #gradle

🚀 5 Things You Probably Didn’t Know About Kotlin Coroutines Most developers already know that Coroutines are lightweight threads. But Coroutines are much more powerful than that. Let’s look at some features that make them a game-changer 👇 🔹 1. Structured Concurrency = No Memory Leaks Coroutines launched inside a scope (viewModelScope, lifecycleScope) are automatically canceled when the scope ends. 👉 No more manual cleanups, no hidden leaks. 🔹 2. CoroutineContext = Full Control Every coroutine runs in a CoroutineContext (Dispatcher, Job, Name). 👉 You can easily switch from IO thread to Main thread without boilerplate code. 🔹 3. Flows & Channels for Reactive Streams Coroutines are not just about async calls — they also support reactive programming. 👉 Flow emits data only when collected (cold stream), saving battery & resources. 🔹 4. Built-in Exception Handling No more messy thread exception handling. 👉 Coroutines let you use CoroutineExceptionHandler for clean, centralized error handling. 🔹 5. SupervisorJob = Independent Children When one coroutine fails, others can still continue if launched with SupervisorJob. 👉 More stability in production apps. ✅ In short: Coroutines are not just lightweight threads — they’re a modern concurrency framework designed for scalability, stability, and cleaner code. 👉 Have you explored these advanced Coroutine features yet? #Android #Kotlin #Coroutines #MobileDevelopment #AsyncProgramming

🛠️ Kotlin + Compose + Wasm. Running entirely in the browser. No JVM. No Android runtime. Just Kotlin/Wasm executing natively. Here’s what’s happening in this Playground demo: 1️⃣ Compose Multiplatform provides the UI toolkit (Composable functions, theming, state). 2️⃣ Code is compiled to WebAssembly (Wasm) → runs directly in the browser’s VM. 3️⃣ The runtime integrates with the browser canvas via ComposeViewport, so you get real Compose rendering without HTML/CSS. 4️⃣ State management (remember, mutableStateOf) works exactly as it does on Android. 5️⃣ Dark/Light theme toggling is powered by MaterialTheme + darkColors()/lightColors(). Why this matters: ✅ Same Kotlin source runs on Android, iOS, Desktop, and Web. ✅ Removes the “web vs mobile” barrier — Compose is becoming a true universal UI toolkit. ✅ Wasm ensures near-native execution speed, unlike JS transpilation hacks. This is still experimental (you’ll see the OptIn(ExperimentalComposeUiApi::class)), but the fact that I can flip a Dark Mode switch in a browser with Compose code feels like a leap forward. I’d love to hear what others in the Kotlin/Android/WebAssembly space think. 👇 #Kotlin #ComposeMultiplatform #WebAssembly #JetpackCompose #CrossPlatform #FrontendEngineering #AndroidDev #KotlinWasm #UIFramework JetBrains

Android's 16KB Page Alignment: Stop the headache. You probably don't need to worry about it. 🤔 Ever seen that warning about 16KB page alignment and wondered if you need to do a deep dive to fix it? Let's clear it up. Most of the time, you can just ignore it. ➡️ When should you care? The short answer: It ONLY matters if your app uses native libraries (.so files). That's it. This is common if you're working with: 🎮 Game engines (Unity, Unreal) 🖼️ Heavy image or video processing (FFmpeg, OpenCV) ⚙️ Your own custom C/C++ or Rust code If your app is 100% Kotlin/Java, you have nothing to worry about. ➡️ How do you check if you're aligned correctly? If you do use native libraries, the fix is simple. 1. Open your app in Android Studio's APK Analyzer. 2. Navigate to the lib folder and find your .so file. 3. Look for these two magic words: ✅ Compression: Uncompressed ✅ Alignment: 16k If you see that, you're golden! This is usually handled automatically by modern Android Gradle Plugin versions. The takeaway: No native libraries = No headache. Did this clear things up for you? #AndroidDev #Android #Kotlin #MobileDev #AppDevelopment #PerformanceOptimization #Flutter

🛠️ Kotlin + Compose + Wasm → Running entirely in the browser. No JVM. No Android runtime. Just Kotlin/Wasm executing natively in your browser’s VM. In this Playground demo you’ll see: 1️⃣ Compose Multiplatform powering UI (Composable functions, theming, state). 2️⃣ Code compiled to WebAssembly (Wasm) → executes directly in the browser. 3️⃣ Real Compose rendering via ComposeViewport, no HTML/CSS needed. 4️⃣ State (remember, mutableStateOf) works the same as Android. 5️⃣ Dark/Light mode toggling with MaterialTheme. ✅ Why it matters: Same Kotlin source on Android, iOS, Desktop, Web. Removes the “web vs mobile” gap → one toolkit for all. Near-native execution speed thanks to Wasm. Still experimental, but flipping a Dark Mode switch in the browser with Compose feels like the future 🚀 👉 Full breakdown + code here: 

🔸 That’s true, I’m speaking from experience with React Native. It’s crucial to check for cross-compatibility between library versions; otherwise, you might run into build errors or unexpected app crashes. It’s hard to list every required library upfront, but you can start by verifying the most commonly used ones like React Navigation, Axios, React Native Reanimated, React Native Gesture Handler, Async Storage, and React Native Vector Icons #reactjs #android #softwaredevelopment #technology #playstore #programming #ig