IV. PERFORMANCE OF KMCPY kMCpy has been developed in python, a high-level, humaninterpretable language that combines flexibility and ease of programming. Since python is one of the most widely used programming languages both in the fields of materials informatics and data science, it provides a set of readily available tools and libraries that can be used to accelerate the development of new codes and libraries. Among them, we utilise a JIT compiler, Numba 72 , to increase the computational performance of kMCpy. Specifically, Numba translates the most numerically demanding part of kMCpy into optimized machine code.