Cadillac puts batteries in different places. The Escalade has its battery under the bonnet, like other GM trucks. Saloons such as the ATS, CT5 and CT6, and later CTS models, carry theirs in the boot behind the trim, with separate jump-start posts under the bonnet. So a Cadillac that will not start may also have a boot that will not open. The technician powers the car through the bonnet posts first, opens the boot, then works on the battery itself.
Recent Cadillacs with automatic stop-start use AGM batteries, and the car monitors charge through a sensor on the battery cable. Coding is not normally required on GM vehicles, but the sensor has to be refitted properly and the car needs a few hours at rest to learn the new battery's state. With this much equipment on board, seat memory and large displays included, a memory saver during the swap avoids a long list of resets.