DevOps engineer moving to physical CCTV biz – how to manage the mess?

I’m a DevOps engineer in Cape Town. I started a CCTV/monitoring biz thinking it was "infrastructure as hardware." I was wrong.

I’ve been bleeding money on a school project due to:

Voltage drop/PoE limits over 100m.

Bad labor: No "git revert" for a hole drilled in the wrong place.

Workmanship: My "clean code" mindset is failing in the "meatspace" of messy cabling.

To those who moved from software to physical infrastructure:

How do you enforce "clean" workmanship with manual labor?

What are your must-have tools for the physical layer?

How do you stop "scope creep" when you're 10 meters up a ladder?