Maciej Jankowski contributed to the silx-kit/silx repository by refining the user experience for ellipse masking in the GUI, focusing on clarity and usability. He corrected the tooltip to accurately describe the ellipse masking feature, addressing user confusion and reducing potential support needs. Using Python and PyQt, Maciej also experimented with a performance safeguard by adding a warning dialog before plotting large 3D cube data, then prudently reverted the change to maintain workflow smoothness. His work demonstrated careful debugging, disciplined version control, and thoughtful risk assessment, resulting in targeted improvements that balanced user guidance with overall application stability and performance.