"TaaS" is an open-source product that allows you do achieve the "correct" way of doing integration testing across a variety of products via Test Automation.
Typically in organizations, there are multiple projects / products. Many organizations like to have a common Test Automation solution across these products in an effort to standardize the framework.
However, this is not a good idea! Each product should be tested using the tools and technologies that are "right" for it. Yet - these different products talk with each other and you need to test the integration between them in an automated way.