𝗞𝗠𝗣 - 𝗛𝗼𝘄 𝘁𝗼 𝘀𝘁𝗮𝗿𝘁 𝘀𝗵𝗮𝗿𝗶𝗻𝗴 𝗰𝗼𝗱𝗲 𝗶𝗻 𝗲𝘅𝗶𝘀𝘁𝗶𝗻𝗴 𝗔𝗻𝗱𝗿𝗼𝗶𝗱/𝗜𝗢𝗦 𝗮𝗽𝗽𝘀 ? Most companies don't start Kotlin Multiplatform greenfield. They have an existing Android repo and an existing iOS repo, both already shipping, and the real question is: how do you share logic without merging them or rewriting either one? Built a working demo: extracted a loan EMI calculator that existed twice, once in Kotlin and once in Swift, and moved it into its own small Kotlin Multiplatform module; it had been quietly able to drift out of sync. Published it in two ways: JitPack for the Android repo, and a Swift Package pointing at a released XCFramework for the iOS repo. Neither app repo touches the other's code. 81 lines of duplicated logic gone (37 Kotlin + 44 Swift), replaced with one 67-line shared implementation both platforms now depend on. Verified identical output across 7 test cases 100% match, checked with a real Gradle test run against the JitPack artifact and a real xcodebuild test run against the SPM-resolved XCFramework, not just claimed. Full before/after + step-by-step migration guide in the repo. 🔗 Shared module: https://github.com/ranab4b/kmp-shared-business-logic 🔗 Before/after demo + migration guide: https://github.com/ranab4b/kmp-adoption-before-after