Designs a ransomware-resilient backup strategy using the 3-2-1-1-0 methodology (3 copies, 2 media types, 1 offsite, 1 immutable/air-gapped, 0 restore errors), configuring RPO/RTO-aligned schedules, isolating backup credentials, and automating restore testing. Use when planning ransomware backup resilience or air-gapped/immutable backup architecture.
