Typically an experienced software engineer will be your team lead working with managers and developers to provide important direction and ensure best practices.
The number of engineers will depend on the project. Support Engineers participate in the full life cycle development, from specification and design through implementation, testing and support.
Implementing manual system testing and automated testing scripts, the QA engineer prevents defects and minimizes risk following the ISTQb testing principles, the Agile Manifesto and DevOps culture.