KMP in Practice: Real world case studies

In this session we will delve into Kotlin Multiplatform (KMP) and explore its real world applications and case studies. Participants will have the opportunity to learn from developers who have successfully incorporated KMP into their projects across platforms like JVM, Android, iOS and Web. The discussion will cover the following topics;

*Successful Implementations; We will provide walkthroughs of how KMP has been effectively used in various sectors such as finance, healthcare and entertainment. Specifically we will showcase an entertainment app called JioCinema that utilizes KMP.

*Overcoming Challenges; Gain insights into obstacles faced during KMP implementation including platform specific integration issues, performance optimization and maintaining code quality across different platforms. We'll discuss solutions and workarounds that have been employed.

*Performance Metrics; Analyze the performance enhancements achieved through KMP by presenting numbers and metrics obtained from real case studies.

*Best Practices; Take away key insights and best practices for developers who are considering adopting KMP. This includes information on code sharing strategies testing methodologies and deployment approaches.

*Future Potential; Explore the evolving landscape of KMP and its impact on the future of cross platform development.

This session is designed for Kotlin developers with to advanced skills who are interested, in multiplatform development.

This event aims to provide attendees with insights and practical knowledge on how to effectively implement KMP in their own projects. It will showcase the potential of KMP to streamline development processes and improve app performance, across platforms.

Transcript

1. Adit Lal | 2024 Journey of ups/downs for the real-world KMP apps KMP in Practice: Real world case studies
3. Coroutines Null-Safety Extension-Functions Smart-Casts Delegated-Properties Versatility on the Server Side streamlined approach Open Source Modern Language Features Uni fi ed Codebase
4. Kotlin multipla tf Source - https://shorturl.at/xyAPX
5. Kotlin multipla tf orm
6. Kotlin multipla tf orm
7. Kotlin multipla tf orm
8. Kotlin multipla tf orm
9. Kotlin multipla tf orm
10. Kotlin multipla tf orm
11. Multiplatform libraries
13. Compose Multiplatform
15. Fleet
16. • Flexibility to choose what is shared and what not • Shared code lowers the effort, cost per feature • Shared code ensures consistency amongst platforms KMP - Buy in
17. UseCases - Greenfield #1 a ndroidApp (module) iosApp (module) sh a red (KMP module) a ndroidM a in(source) commonM a in(source) iOSM a in(source) …(source)
18. UseCases - Greenfield #2 a ndroidApp (module) iosApp (module) a n a lytics (sh a red) Network (sh a red)
19. UseCases - Brownfield #1 Android Project Regul a r Android code sh a red (KMP module) a ndroidM a in(source) commonM a in(source) iOSM a in(source) iOS Project Regul a r iOS code Dependencies m a n a gement • Coco a Pods • Swift P a ck a ge M a n a ger • M a nu a l fr a mework
20. UseCases - Brownfield #2 Android Project Regul a r Android code sh a red (KMP module) a ndroidM a in commonM a in iOSM a in iOS Project Regul a r iOS code Dependencies m a n a gement • Coco a Pods • Swift P a ck a ge M a n a ger • M a nu a l fr a mework a n a lytics (sh a red) Network (sh a red)
21. Adding Multiplatform Mobile to Your Projects • Start small • Keep your shared API simple • Think like a library developer • Implementation should not impact API • Minimise accessibility of everything • Coexist peacefully with (both) platforms
22. Architecture No Silver Bullets
23. Architecture No Silver Bullets Multi-layer Architecture
24. Multi-layer Architecture P r esentation Domain Data
25. Multi-layer Architecture P r esentation • Sharing is possible to a degree • Prefer MVVM and MVI • Decompose, moko-mvvm • Needs experienced team to share
26. Multi-layer Architecture • Perfectly shareable • Services, Models, Gateways Domain
27. Multi-layer Architecture • Usually shareable • Repositories, DTOs and entities • SQLDelight, Realm, Ktor Client, Apollo, kotlinx-datetime Data
28. Multiplatform UI
29. Dependency Injection
30. Ideas, mistakes and learnings
31. Ideas, mistakes and learnings expect fun debugLog(tag: St r ing, message: St r ing) Expect/Actual
32. Ideas, mistakes and learnings expect fun debugLog(tag: St r ing, message: St r ing) Expect/Actual impo r t and r oid.util.Log actual fun debugLog(tag: St r ing, message: St r ing) { Log.d(tag, message) } impo r t platfo r m.Foundation.NSLog actual fun debugLog(tag: St r ing, message: St r ing) { if (Platfo r m.isDebugBina r y) { NSLog("%s: %s", tag, message) } }
33. Ideas, mistakes and learnings inte r nal inte r face XmlFetche r { suspend fun fetchXml(u r l: St r ing) : Pa r se r Input } Interfaces inte r nal class JvmXmlFetche r ( p r ivate val callFacto r y: Call.Facto r y, ) : XmlFetche r { ove r r ide suspend fun fetchXml(u r l: St r ing) : Pa r se r Input { val r equest = c r eateRequest(u r l) r etu r n Pa r se r Input(inputSt r eam = callFacto r y.newCall( r equest).await()) } }
34. Ideas, mistakes and learnings inte r nal inte r face XmlFetche r { suspend fun fetchXml(u r l: St r ing) : Pa r se r Input } Interfaces inte r nal class IosXmlFetche r ( p r ivate val nsU r lSession: NSURLSession, ) : XmlFetche r { ove r r ide suspend fun fetchXml(u r l: St r ing) : Pa r se r Input = suspendCancellableCo r outine { continuation - > . . . } }
41. Gotcha’s •No namespaces •No default parameters •Enums are not Swift-friendly (no values) •Sealed classes are simple classes •Coroutines without cancellation •Flows
44. Make it a team effort
45. Create a library
48. How to publish: Android
52. How to publish: iOS
61. Where to start
62. You have a blank canvas
64. @marcoGomier • Boring code to write multiple times • Code/feature that centralizes the source of truth • Code/feature that can be gradually extracted Where to start?
65. Kotlin multipla tf orm - 🛠 Tooling 📦 Storage 🏗 Architecture 🔑 Crypto 🗃 Serializer - code and tools - 🍎 Compose UI 🧮 Arithmetic - 📋 Log 📱 Device 🔍 Analytics 📁 File ⏰ Date-Time - 🎨 Graphics 🛢 Resources - 🌎 Network 💉 Dependency Injection 🩺 Test 🚀 Language extensions ➿ Asynchronous 🧩 Service SDK 🔧 Utils
66. Kotlin multipla tf orm - 2x faster to develop your features business logic - 2x faster writing unit tests - One tech stack - consistency achieved across pla tf orms conclusions
67. Kotlin multipla tf orm - sta rt small, don’t try to reach 100% of shared logic - be extremely careful with all updates - IDEA, JDK, kotlin, libraries - everything. - keep versioning in mind Suggestions
68. Kotlin multipla tf orm Kotlin Slack Kotlin O ffi cial Kotlin Training Kotlin by: - h tt ps://jakewha rt on.com/presentations/ - h tt p://antonioleiva.com/kotlin Resources Pay attention to this
69. Kotlin multipla tf orm h tt ps://github.com/joreilly/PeopleInSpace h tt ps://github.com/joreilly/ClimateTraceKMP h tt ps://github.com/halcyonmobile/Multipla tf ormPlayground About Kotlin Multipla tf orm project with Swi ft UI, Jetpack Compose, Wear Compose, Compose for Desktop, Compose for Web and Kotlin/JS + React clients along with Ktor backend. Resources
70. • https : //kotlinlang . org/docs/multiplatform . html • https : //kotlinlang . org/docs/native-overview . html • https : //kotlinlang . org/docs/js-overview . html • https : //kotlinlang . org/docs/multiplatform-share-on-platforms . html • https : //kotlinlang . org/docs/multiplatform-connect-to-apis . html • https : //devstreaming-cdn . apple . com/videos/wwdc/2019/416h8485aty341c2/416/416_binary_frameworks_in_swift . pdf • https : //developer . apple . com/videos/play/wwdc2019/416/ • https : //medium . com/@aoriani/list/writing-swiftfriendly-kotlin-multiplatform-apis-c51c2b317fce • https : //kotlinlang . org/docs/native-objc-interop . html • https : //speakerdeck . com/kpgalligan/kotlinconf-2023-kotlin-mobile-multiplatform-for-teams • https : //speakerdeck . com/kpgalligan/sdk-design-and-publishing-for-kotlin-multiplatform-mobile • https : //kotlinlang . org/docs/reference/native/cocoapods . html • https : //kotlinlang . org/docs/multiplatform-build-native-binaries . html#build-xcframeworks • https : //github . com/touchlab/KMMBridge • https : //github . com/prof18/kmp-framework-bundler • https : //github . com/luca992/multiplatform-swiftpackage • https : //github . com/touchlab/xcode-kotlin • https : //github . com/terrakok/kmp-awesome • https : //github . com/AAkira/Kotlin-Multiplatform-Libraries • https : //github . com/touchlab/CrashKiOS • https : //www . droidcon . com/2023/07/31/10-myths-about-crossplatform-mobile-development-with-kotlin/ • https : //blog . jetbrains . com/kotlin/2023/11/kotlin-multiplatform-stable/
71. Thats all folks! https://topmate.io/aditlal 🔗aditlal.dev travelwithadit