Management of the data processing & Run-by-Run simulations in KM3NeT

The KM3NeT collaboration is constructing two underwater neutrino detectors in the Mediterranean Sea: ARCA, optimized for the observation of astrophysical neutrinos, and ORCA, designed to determine the neutrino mass hierarchy by detecting atmospheric neutrinos. As the detector configurations are growing and, thus, the amount of recorded data is increasing, efficient data quality and data processing management are essential. Data reconstruction and Monte Carlo simulations are performed in conjunction for each data-taking period (run). A Run-by-Run simulation approach is used to reproduce the seawater environmental conditions and possible variations, as well as the acquisition settings for each run, improving processing performance and analysis reliability. To meet computing requirements for portability, reproducibility, and scalability, KM3NeT has adopted Snakemake, a modern workflow management system that streamlines and automates complex data processing tasks while ensuring flexibility and efficiency across different computational environments. This workflow was successfully employed in recent KM3NeT analyses, including the first observation of an ultra-high-energy cosmic neutrino, published in Nature on February 12, 2025.