Building KMP Libraries: The RevenueCat Story | Talking Kotlin #137

Sebastian and Márton discuss building KMP libraries with Jay Shortway, the author of RevenueCat’s Kotlin Multiplatform SDK for in-app purchases. 0:00 Intro 0:44 What’s RevenueCat 4:00 In-app purchases are hard 7:22 The multiplatform SDK – https://www.revenuecat.com/docs/getting-started/installation/kotlin-multiplatform 12:44 The demand for KMP 16:30 Hiring and team structure 18:42 SDKs for any framework – https://www.revenuecat.com/blog/engineering/how-our-hybrids-work/ 21:27 Building on native SDKs 23:45 Improving iOS linking – https://github.com/ttypic/swift-klib-plugin 24:54 The SDK is on GitHub 26:05 Benefits of building on native 28:18 Designing a common API 33:21 Add-on modules for SDKs 37:30 Instant in the standard library – https://github.com/Kotlin/kotlinx-datetime/issues/382 38:04 Returning results from the API 39:53 API design decisions 44:57 Codegen opportunities 45:48 The best things about KMP 47:07 KMP improvements wishlist 48:28 The KMP journey 49:45 Wrap-up RevenueCat KMP SDK – https://www.revenuecat.com/docs/getting-started/installation/kotlin-multiplatform How we built the RevenueCat SDK for Kotlin Multiplatform – https://www.revenuecat.com/blog/engineering/how-we-built-the-revenuecat-sdk-for-kotlin-multiplatform/ Hybrid SDK Architecture at RevenueCat – https://www.revenuecat.com/blog/engineering/how-our-hybrids-work/ ttypic/swift-klib-plugin on GitHub RevenueCat/purchases-kmp on GitHub – https://github.com/RevenueCat/purchases-kmp Consider moving `Instant` and `Clock` to the standard library · Kotlin/kotlinx-datetime – https://github.com/Kotlin/kotlinx-datetime/issues/382 RevenueCat openings – https://job-boards.greenhouse.io/revenuecat Hosts: Sebastian Aigner Website – https://sebi.io/ Bluesky – https://bsky.app/profile/sebi.io Márton Braun Website – https://zsmb.co Bluesky – https://bsky.app/profile/zsmb.co Guest: Joop Korteweg – https://x.com/JayShortway