We use ServeTheWorld as our primary validator partner, with our hardware hosted in their high-security data centre in Oslo, Norway.
They provide:
24/7 staffed access control and on-site security personnel
Biometric access (facial recognition) plus secured entry perimeters
Redundant power (dual feeds, UPS & generator backup) and environmental controls (fire suppression, HVAC)
Controlled physical access and strong location security under Norwegian law
Latitude.sh - Singapore
As a backup we also host hardware with Latitude.sh in Singapore, ensuring global redundancy and fail-over capability.
The Latitude.sh site offers:
A globally distributed data-centre network (including Singapore) allowing rapid deployment and high reliability
Strong physical security policies — their "Security at Latitude.sh" documentation outlines robust information security governance (confidentiality, integrity, availability) for staff, partners, and hardware
Infrastructure built for secure workloads: private networking options, DDoS protection and network isolation support