Indie developer sells 2,500 units of MIDI recorder, says software was the hard part

Chip Weinberger, a software engineer turned hardware entrepreneur, has sold over 2,500 units of the Jamcorder, an automatic MIDI recorder that captures piano performances without any user input. Contrary to the common startup belief that hardware is the biggest challenge, Weinberger found the physical build surprisingly straightforward — he hand-assembled the first 500 units in just four days with no design changes required. The device's circuit board uses only 25 components, mostly off-the-shelf parts, and the enclosure was designed for simple injection molding with a single screw per unit. The real bottleneck was software: firmware, a companion app, and manufacturing tools totaled around 200,000 lines of code that took more than three years to write, all before AI coding assistants were available. Weinberger shared the lessons on his personal blog, advising fellow hardware makers to target at least 70% gross margins and avoid single-source components.