Warning: lost a client's QuickBooks data on a Friday, and the backup I trusted was 8 months old
Client calls me frantic on a Friday at 6pm because their QuickBooks file won't open and payroll runs Monday. I check their backup drive and the most recent file is from 8 months back, because their old tech set it up once and nobody ever checked it. So I drove to their office in Council Bluffs, ran data recovery on the dead drive until 1am, and got 95% of the file back but the last two weeks of invoices were gone. They had to call every vendor that weekend and rebuild those entries by hand. Now I test restore every single backup I manage, no exceptions, and I tell clients the schedule up front. What is your rule for proving a backup actually works instead of just trusting the light is green?
Learned this the hard way too, because I used to just look at the backup software and see a green check and figure it was fine. Now I actually pull a random file out and open it every month, since a backup that won't restore is just a file sitting there doing nothing. If you can't prove the restore works with your own hands, you don't have a backup, you have a hope.