Designing Cloud Security Architecture for Regulated European Enterprises

European financial services and telecom operators are under more regulatory scrutiny over their cloud environments than at any point since cloud adoption began. DORA, NIS2 and national supervisory expectations now reach directly into how cloud architecture is designed, not just how it is operated.

The organisations we see struggle are typically those that adopted cloud incrementally, team by team, without an enterprise-wide reference architecture. The result is inconsistent identity models, uneven network segmentation, and data protection controls that vary depending on which team built which workload, none of which holds up well under regulatory examination.

A defensible cloud security architecture starts with a small number of hardened landing zones, not one per project. Identity and access management needs to be centralised and enforced consistently across providers, network segmentation must isolate workloads by data sensitivity rather than convenience, and encryption and key management need a single, auditable model regardless of which cloud platform is in use.

Multi-cloud adds a further layer of complexity that many organisations underestimate: security controls that work well in one provider do not translate directly to another, and regulators increasingly expect evidence of consistent control regardless of platform. This is where a documented reference architecture, not a set of provider-specific configurations, becomes essential.

Getting this right is not simply a compliance exercise. Enterprises with a coherent cloud security architecture move faster on transformation initiatives, because new workloads inherit a proven security model rather than requiring bespoke review each time. Regulatory readiness and delivery speed, done properly, are the same outcome.