How to build debs for ubuntu from source

After cloning from source, checking out "applied/ubuntu/jammy-updates" and compiling with: (all build deps are pre-installed)

    meson setup build/ && meson compile -C build/

.. how do I then create all the individual deb files? I tried finding any kind of documentation, even trying various commands like "make -j4 debian/rules build", with no success. I also tried finding out how Ubuntu themselves does it, if Ubuntu has some kind of CI job which builds these debs, but if so I couldn't find that either.

Any links or a pointer in the direction would be greatly appreciated. Sorry for asking such beginner question, but really couldn't find any documentation at all of building systemd debs.