TOSCA is an OASIS open standard, and is an abbreviation for Topology and Orchestration Specification for Cloud Applications. It provides a domain-specific language to describe how an application should be deployed in the cloud (the topology), which and how many resources it needs, as well as tasks to run when certain events occur (the orchestration). When I initially came across this standard, I was (and still am) interested in how far this goes. The promise of declaring an application (and even bundling the necessary application artefacts) within a single asset and then using this asset to deploy on whatever cloud is very appealing to an architect. Especially in organizations that have a multi-cloud strategy.
Software as a Service (SaaS) solutions are often a quick way to get new capabilities into an organization’s portfolio. Smaller SaaS solutions are simple, web-based solutions which barely integrate with the organization’s other solutions, besides the identity and access management (which is often handled by federated authentication).
More complex or intermediate solutions require more integration focus, and a whole new market of Integration Platform as a Service (iPaaS) solutions came up to facilitate cross-cloud integrations. But even without the iPaaS offerings, integrations are often a mandatory part to leverage the benefits of the newly activated SaaS solution.
In this post I want to bring some thoughts on the integrations that might be needed to support customizing a SaaS solution.