Agile Embedded Podcast E93: Hardware-Software Co-Development with Tobias Kästner

Jeff and Luca talk with Tobias Kästner about bridging agile software development and hardware engineering. Tobias shares lessons from medical devices, where six-month hardware cycles became a major bottleneck. The core problem: how do you evolve hardware and software together when requirements keep changing? Tobias describes reducing hardware iterations from six months to three weeks by breaking monolithic PCB designs into modular "shield" boards—like Arduino's ecosystem, but custom-built for specific needs. Technical details include: version controlling schematics in Git (with SHA-1s on silkscreen!), automating schematic merges, and using RTOSs like Mynewt and Zephyr for plug-and-play firmware. The approach scaled to 120-person teams across multiple products. It's about changing how hardware and software teams work together, understanding interdependencies between architecture, organization, and information flow. 0:00 Welcome and Introductions 0:52 From Physicist to Engineer 3:59 The Six Month Wait 7:59 Discovering Agile Methods 10:50 Faster Hardware Cycles 12:29 Tick Tock Sprint Alignment 18:13 Modular Shield Architecture 29:03 Git Version Control 35:55 Firmware Architecture Evolution 39:17 Zephyr RTOS Solution 45:37 Scaling to Large Teams 51:38 Closing and Contact