The UNICORN Cloud Operations Platform reference architecture is divided into three layers (Figure 1):


The Cloud Application Development and Management Interface Layer – the layer hosting the tools for developers to design, deploy and manage portable and interoperable cloud applications with security, data privacy, monitoring and elasticity by design enforced while spanning across multiple availability regions and cloud sites.


The Orchestration, Enforcement and Governance Layer (UNICORN Cloud Operations Platform), which is the core platform hosting the H2020 project's UNICORN services required for continuous resource allocation, application lifecycle management, monitoring, auto-scaling, security enforcement and vulnerability assessment.


The Multi-Cloud Execution Environment Layer, which is the layer hosting deployed cloud applications spanning across multiple availability regions or cloud sites with their deployment abstracted from the underlying cloud infrastructure.