My 36” Cattura is installed directly behind our 36” GE Cafe induction cooktop. Extra space was cut immediately behind the cooktop’s hole (there’s no divider; the holes are merged into one larger opening) to account for both appliances. This attached photo shows the downdraft (closed/stowed) behind the range:

This photo shows under the counter (top drawer removed). We went for side venting (and option with this 36” model) so you can see the vent fitting that attaches and increases in size to a regular 8” vent pipe. That goes downward through the floor (this is a corner of our kitchen island and is a blank/void space) into the basement and connects to the motor/blower suspended from the ceiling. It is then vented out through a vent on the side of the house (with a bit of work to get above the foundation and in between the joists).