Egor K. focused on improving the build process for the wallet-core repository by addressing Kotlin expect/actual warnings that affected modules using multiplatform declarations. He resolved these issues by introducing the -Xexpect-actual-classes compiler argument within the Gradle build configuration, which reduced warning noise and streamlined compilation. This adjustment enhanced build stability and improved CI reliability, making the development workflow smoother for Kotlin-based modules. Egor’s work, though limited to a single bug fix during the month, demonstrated a strong understanding of build configuration and Kotlin’s multiplatform features, ultimately reducing maintenance overhead and preparing the codebase for future multiplatform development.