Testers fit into the Scrum framework based on their competence rather than their role. Someone with testing competence can help with code and architecture design, writing acceptance criteria, testability, and test automation. They can also coach other members of the scrum team and provide a tester's perspective during retrospectives. While everyone on the scrum team is responsible for testing, someone with strong testing competence can help handle more complex testing problems. Their unique skills and perspective help support the overall scrum team.