ReMIX35 is an open-hardware reinterpretation of the Prusa MK3.5 electronics — a fully community-driven mainboard designed to bring modern 32-bit performance and transparent engineering to the iconic MK3S/+ platform. Built around the STM32F427 microcontroller and Trinamic TMC2130 drivers, ReMIX35 ensures binary compatibility with the original Prusa firmware while staying true to open design principles. What began as a reverse-engineering study evolved into a complete hardware rebuild — adapting the xBuddy form factor to the classic Einsy RAMBo layout, analyzing every subsystem, and testing the board extensively on real printers. The result is not just an upgrade, but a dive into the engineering behind one of the most successful open 3D printer architectures — a project built by and for the community.