Using microservices for non-intrusive customization of multi-tenant SaaS.

Enterprise software vendors often need to support their customer companies to customize the enterprise software products deployed on-premises of customers. But when software vendors are migrating their products to cloud-based Software-as-a-Service (SaaS), deep customization that used to be done on-premises is not applicable to the cloud-based multi-tenant context in which all tenants share the same SaaS. Enabling tenant-specific customization in cloud-based multi-tenant SaaS requires a novel approach. This paper proposes a Microservices-based non-intrusive Customization framework for multi-tenant Cloud-based SaaS, called MiSC-Cloud. Non-intrusive deep customization means that the microservices for customization of each tenant are isolated from the main software product and other microservices for customization of other tenants. MiSC-Cloud makes deep customization possible via authorized API calls through API gateways to the APIs of the customization microservices and the APIs of the main software product. We have implemented a proof-of-concept of our approach to enable non-intrusive deep customization of an open-source cloud native reference application of Microsoft called eShopOnContainers. Based on this work, we provide some lessons learned and directions for future work.