Worked on the effekt-lang/effekt repository to enhance user guidance and error diagnostics for developers using the Effekt language. Improved the IO tour documentation by adding explicit instructions for importing io and promise modules, making feature discovery more intuitive for new users. Addressed a bug in the compiler’s parser and exhaustivity checker to ensure unreachable val-else warnings now report accurate source positions, streamlining the debugging process. Leveraged Scala programming and compiler design expertise to deliver these targeted improvements, focusing on documentation clarity and robust error handling. The work contributed to a smoother onboarding experience and more precise diagnostics for Effekt users.