Release train engineer (RTE)
The Release Train Engineer is the chief Scrum Master of an Agile Release Train, facilitating PI Planning, removing impediments across teams, managing risks and dependencies, and coaching the ART on SAFe practices. The RTE is a servant-leader role: not a manager of the included teams, but the orchestrator of their cadence and the keeper of the program-level events.
The RTE role is the difference between a SAFe ART that runs well and one that drifts into ceremony theatre. A good RTE knows every team's PI Objectives, every cross-team dependency, every active risk, and every Business Owner's expectations, without becoming a bottleneck for any of them. The role typically requires 100% time at scale; trying to combine it with a Scrum Master role for one of the teams almost always shortchanges both. Career path: most RTEs come up from Scrum Master, sometimes from program management or technical PM; the technical depth required varies by ART complexity.