Developed robust SCM-style support for XYZTrajectoryFile within the SCM-NV/PLAMS repository, focusing on enhancing trajectory file I/O reliability and consistency. Leveraged Python to implement comprehensive unit tests, including fixtures and string assertions, that validate round-trip reading and writing of trajectory data with the 'scm' style. This approach ensured that output formatting remained consistent and regression risks were minimized. Expanded the trajectory I/O test suite to detect issues early and documented expected behaviors to support ongoing code maintainability. Demonstrated skills in file I/O, testing, and trajectory analysis, contributing to improved user confidence in handling trajectory data within scientific workflows.