Tested backups and a clear, practised plan to bring the firm back, whether it's a deleted file, a dead server, or a bad day nobody saw coming.
Nobody plans for the server dying the week before a deadline. We make sure that when it does, the answer is “we've got this,” not a scramble and a sinking feeling.
Plenty of firms discover their backups don't work at the worst possible moment. We remove that risk by restoring regularly and keeping copies attackers can't reach.