> Embedded covers a wide range of systems. Are we talking about a NAS
> box with lots of storage, a WIFI access point, the center console of
> your auto, a drone?

That is an excellent follow-up question, which I should have addressed and
clarified. I am looking more like the console of the auto. An example would
be making a pinball machine, or generally something that does not really
require to store long term data, would be expected to shutoff abruptly (main
issue with keeping data integrity), and have quick boot-up times.

> In generally, i just run Debian on everything, making use of the
> bootloader which is already there, and if needed, adding extra storage
> via a USB stick or SD card.

Everything needs a bootloader of sorts. I am more interested in additional
architectural design of a robust embedded system. An example will help. This
is Intel's "Euclid" depth-camera device: https://robots.ros.org/intel-euclid/

Runs some Ubuntu flavour of Linux. I played with this hardware recently. It
boots Ubuntu, starts X, which it displayes through HDMi, and becomes an access
point, through which one can access the main functionality of the device (the
depth-sensing camera). The system has a single button to turn it on, and one
would never know it runs a full-blown OS behind it if they did not care.

I want to build my own embedded Linux-based OS out a different distro. I know
one can use Buildroot, etc, but I would like some ideas on architecting such
a solution rather than picking one.