Integration of non-existing SaaS solutions consists of the use of APIs (Application Programming Intеrfacеs) to connect the different software systems. APIs are the tools that allow the data to be exchanged and the functionality to be shared between the applications, hence, the communication among them is smooth. SaaS providers usually offer documented APIs, which makes it possible for developers to integrate third-part services or customize the pre-existing service to fit the specific business needs.