You mean things like cloud-init, juju, a ton of work they do directly upstream on openstack, hardware certifications (which include things like getting vendors to upstream their drivers into the mainline kernel — something even Google has struggled with for Android), and making it more feasible for more companies to run Linux by providing the sort of long-term support that the community just doesn’t prioritise?














…that’s not what they’re doing though?
Those patches get either pulled from upstream or built in-house and shared to upstream. Just like in Debian, and just like in the regular Ubuntu releases, the package is based on some upstream version and then the deb packaging applies the patch sets as listed in the diff tarball.
Here’s what the latest kernel for Ubuntu 26.04 look like: https://launchpad.net/ubuntu/+source/linux/6.17.0-6.6
Those same tarballs are available for any Ubuntu package by running
apt source <pkg>as long as you’ve configured the matchingdeb-srcrepositories.