I'm taking the Airbus A320 for illustration, but any comparable civil aircraft can be explained. By the way, the electronics bays of the A380 and of the A320 look the same; apparently no big change occurred.
On this aircraft the main electronics bay 80 VU contains multiple systems:
A320: 80VU avionics racks, source
A320, photo by B-2230, source: JetPhotos
Question: How is the electronic equipment locked (it seems there are two mobile screws) and how are the wires connected? Details will be appreciated: standards, diagrams, images...