At Analog Devices, ensuring reliable hardware and software integration is critical to delivering high-quality solutions. To address this, we built a fully automated hardware test harness that enables continuous validation across diverse platforms. The system integrates hardware and automated workflows, allowing us to rapidly detect regressions and streamline feedback to developers. By combining Linux-based testing, CI pipelines, and Python automation, the harness provides reproducible results at scale and supports both internal and open-source toolchains such as MATLAB. This talk will share the architecture, challenges, and lessons learned from developing and managing the test harness, including strategies for handling hardware variability, maintaining stability, and integrating with existing CI/CD systems. Attendees will gain insights into designing effective hardware-in-the-loop validation environments, scaling test coverage, and building processes that bridge hardware and software reliability. Ultimately, the test harness enables faster iteration, improved quality, and stronger collaboration across engineering teams.