My old IoT (but without the cloud) startup's products. I still have a few left over that I wanted to use around my house. I had a crosscompile and flashing process set up that worked well in 2011, fixed it in 2014, but it's broken again. All of the embedded software was designed around a realtime kernel and SysVInit, and SystemD is just one obstacle of a thousand that has to be surmounted to even get the hardware and software to boot in a special snowflake setup on a newer Debian, let alone something reliable and repeatable.