The video spends a little time showing some of the computer modeling and designing of the stunt, but most of the video covers the practice runs done with a test car. Jaguar set up its prototype offset ramp for initiating the roll, and had a massive airbag set up for the test car to land in. And early on, to make sure the stunt driver wasn't hurt, they rigged up a Land Rover Evoque with autonomous driving equipment to do the first runs. Later the stunt driver took a few turns.
The testing resulted in flips and tumbles you've only seen with Hot Wheels cars. It's so strange and fun to see a full-size car launched this way. Once the team finally had the jump pretty well dialed in, the stunt driver was able to test it launching from ramp to ramp, and then eventually do it in the production E-Pace at the crossover's reveal.