The KM3NeT Collaboration is developing two deep-sea neutrino telescopes in the Mediterranean
Sea. These telescopes use digital optical modules equipped with photomultipliers and acquisition
electronics. Mounted on vertical strings, thousands of these modules are already in operation.
Once completed, the telescopes will feature over six thousand synchronized modules, creating
one of the world’s most advanced detection networks. This work presents the strategies in the
design, upgrade, and manufacturing of the acquisition electronics boards for KM3NeT to obtain
high-reliability products that can operate in deep sea conditions, 2500 meters deep in the case
of ORCA and 3500 meters in the case of ARCA. Various methods, including FIDES analysis,
Design for Manufacturability (DfM) analysis, Highly Accelerated Life Tests (HALT), Highly
Accelerated Stress Screening (HASS), and functional test benches are employed. In addition, the
ancillary board developed for the debugging of produced boards with problems of synchronization
is presented. The validation workflow follows a structured process for upgrading any acquisition
board, integrating iterative steps to ensure performance and robustness. By adopting an agile-
inspired approach, the methodology prioritizes efficiency and adaptability, fulfilling the tight
production planning of the experiment, while maintaining high-reliability standards.