SaaS architectures are pretty basic. I thought I would write a few words too describe the basics of any SaaS application.
Obviously each SaaS application offers some Core Functionality or Services. This is the core on which a vendor is able to attract customers and earn money. For example – WorkDay is a SaaS vendor that offers HR functionality in the Cloud. The core HR capabilities would fall under the “Core Functionality” bucket.
The core capabilities are also extended by a set of Reporting Services, Identity Services and Integration Services. These are considered the minimum set of capabilities that a SaaS vendor would need to provide from an architectural perspective. Obviously the extent of features and functions provided in each module is based on the several different factors.
Beyond the core architecture, a SaaS application consists of N number on Add on Modules. These are collection of capabilities that clients can choose to buy or not buy. For example, in the HR example, Payroll or Benefits could be considered an Add on Module.
Additionally, a SaaS vendor could provide certain Configurable modules. These would allow customers to customize the capabilities in these modules or affect the capabilities of other modules. Examples of these could be specific modules for governance, compliance and audit.
Two pieces left.
Client Specific modules are modules that a SaaS vendor might choose to develop specifically for a client. The vision would be to build this for a client and later repurpose all or most of the code into an Add on Module or into the Core Functionality.
The last part of the simplified architecture is the 3rd Party Integrations. These are services that the SaaS vendor would write to integrate with external parties. An example in the HR world could be integrating with a Payroll provider to cut the checks, or integrating with a Fidelity like provider for 401K, or integrating with Blue Cross for insurance information.
This is clearly a simplified, non technical view – but will hopefully help describe the basics behind SaaS.



