HYBRID CLOUD ARCHITECTURE FOR SECURE DATA STORAGE AND HIGH-AVAILABILITY ACCESS IN SAUDI ENTERPRISES
Saudi enterprises are modernizing critical information systems while facing strict expectations for data protection, continuous availability and accountable cloud governance. Hybrid cloud architecture has become a pragmatic design pattern because it allows sensitive databases, regulated records and latency-sensitive services to remain under direct enterprise control while elastic public-cloud services support analytics, disaster recovery, software delivery and burst capacity. This review paper synthesises recent work from 2020 to 2025 on hybrid cloud security, private cloud platforms, high-availability storage, cloud threat management and Saudi regulatory alignment. The paper develops an integrated review framework and proposes a reference architecture that combines data classification, encrypted storage, zero-trust access, distributed storage, active-active service routing, immutable backup and continuous observability. The findings indicate that Saudi enterprises should treat hybrid cloud as a governed operating model rather than a simple mixture of local and public infrastructure. Secure storage depends on policy-driven data placement, key sovereignty, identity federation, segmentation and auditable transfer controls. High availability depends on removing single points of failure across proxy, control, data, compute, network and storage layers, with routine failover testing and business-aligned recovery objectives. The review contributes a structured control matrix and implementation roadmap for Saudi enterprises that need scalable digital platforms without weakening confidentiality, integrity or service continuity.