Worked on the dotty-staging/dotty repository to address a critical issue in LambdaMetafactory related to non-primitive lambda return types. Focused on compiler development and JVM backend engineering, the work involved correcting the boxing behavior for lambda returns to align with Android ART runtime requirements. Using Scala and Java, the solution ensured that non-primitive return values were properly boxed, thereby improving runtime compatibility and reducing errors in downstream Android applications. This targeted bug fix enhanced the stability and correctness of lambda handling in the compiler, reflecting a deep understanding of JVM internals and cross-platform runtime constraints within the project.