Job seekers anguish over how they will appear on an interview so much that they often forget that the manager they will report to is also auditioning for them. Your manager has the most power of anyone in the company to advance your career. Before you work for someone make sure they have the capacity to teach you things you don't know and steward your career - either directly or indirectly.
I have had many mentors throughout my career who never knew they were my mentors. I studied their behavior, as well as their sense of process and connection. You dont have to ask someone formally to be your mentor to learn from them
Be selective in who you will work for. Not just what company - what manager. Ask yourself these questions: