Arnez contributed to the espressif/binutils-gdb repository by developing GDB record and replay support for s390 arch15, focusing on accurate state capture and replay for modern z/Architecture targets. He implemented opcode handlers for bit manipulation, arithmetic, and vector operations in C, integrating them into the GDB internals to enhance debugging fidelity and reproducibility. This work addressed the challenge of reliably reproducing intermittent bugs and analyzing complex workloads, reducing time-to-root-cause for developers working with embedded systems. Arnez demonstrated depth in low-level programming, debugging tools, and architecture-specific development, delivering a targeted feature that improved the reliability of the debugging process.