April 2025 – Kotlin/KEEP focused on API-evolution design to improve binary compatibility across library versions. Delivered a design proposal for version-based overloads using @IntroducedAt to mark parameters added in specific library versions, enabling compiler-generated previous overloads and maintaining binary compatibility. The work integrates with existing mechanisms like @JvmOverloads and lays groundwork for safer API evolution. No bug fixes were recorded this period; effort concentrated on design, alignment, and documentation. Impact: reduces breaking changes for downstream clients, lowers migration costs, and stabilizes inter-version interop. Technologies demonstrated: Kotlin language features, annotation-driven API evolution, compiler-interop considerations, versioned API strategy; collaboration and documentation.