I work for AT&T and I can share with you the job description of a System Architect/System Engineer that are interchangeable. A System Architect/System Engineer is "responsible for the fundamental technology work of architecting/designing/building the core frameworks for our system platforms and end to end solutions, including building platform and performance components. Makes high-level design choices and dictates technical standards, tools, and platforms and must have an understanding of systems engineering principles derived from experience. Collaborate with critical stakeholders to understand business needs, priority, and the quality of services to be created or enhanced. Drive solution to be compliant with Target State Architecture. Drive enhancements to Target State Architecture to meet future business needs. Responsible for discovering and identifying any bottleneck gaps such as manual flows that can hinder the services or impact cycle time or cost and resolve them early during the solution, design, and construction phase. Drive research and standardization of platform components that can make up the building blocks from which AT&T will build applications and services. Ensure applications and services are leveraging building blocks whenever possible. Consider the clients non functional requirements such as security, scalability, resiliency, and performance in all solutions. May define and design functional, technical, performance, and reliability solutions in line with client inferred requirements. Solves complex performance issues. Creates massive distributed systems. Creates integrated solutions between legacy and target state solutions. Create vendor guidelines and best practices. Define company technical strategic directions for vendor selection, technology choices, engineering processes, and tools."