Hardware: concept, iteration on paper, CAD, source parts for prototype, build prototype, write firmware, iterate prototype, CAD, source parts for product, find

Hardware: concept, iteration on paper, CAD, source parts for prototype, build prototype, write firmware, iterate prototype, CAD, source parts for product, find a manufacturer for custom parts, final assembly, certification, packaging, logistics, shipping. Software: hire 2 junior programmers, give them the hardware and protocol specs, wait 2 months, upload the executable to a website. The vast majority of "software for hardware" these days is just a GUI sending commands to the firmware over whatever communication channel is available. GPU drivers are pretty much the single example of very complex "software for hardware" in the mainstream market.