Editing is very carefully done on a custom built workstation (I was a computer engineer before photography) with a 3950x 16 core CPU, A Geforce RTX 3080, 128gb DDR4-3200, and stuffed full of ultra fast PCIe Gen4 SSD’s.
It absolutely screams. I also use a MacBook Pro 16 Max for portable edits at destination weddings.
With every wedding using a mix of cameras, I end up with 350gb or so after each wedding. I need every bit of speed I can get.
Backups are handled by a custom built NAS tower running Unraid V6, with 7x10tb hard drives with 2 redundant parity drives. Everything on this box is backed up offsite via Gigabit internet.
Memory cards are copied to the main PC, the NAS & then offsite cloud storage. The cards are then placed in a safe and not touched until my couple get their USB.
I edit using a combination of Photo Mechanic, Capture One, and Photoshop. I don’t use Lightroom much these days it’s a bloated slow mess of a thing and Capture One is lightning fast with great skin tones.
The editing monitor is a Eizo 27" 4k, calibrated weekly with an Xrite i1 display. The day to day monitor is the Alienware 38" Ultrawide.