Arthur de Koos enhanced XLA operation semantics documentation across the Intel-tensorflow/tensorflow and openxla/xla repositories, focusing on clarity, consistency, and alignment with StableHLO specifications. He authored comprehensive updates covering BatchNormGrad, Dot/DotGeneral, and a range of HLO operations, introducing new examples, SVG diagrams, and Markdown-based formatting improvements. Arthur also standardized High Level Optimizer terminology and documented HLO passes, enabling faster onboarding and reducing ambiguity for developers and downstream users. His work demonstrated strong attention to detail in technical writing, compiler design, and data visualization, resulting in more maintainable documentation and improved cross-repository developer experience.