In Discovery episode 2x04, "An Obol for Charon", temporary crewmember
describes her task as follows:
Chief engineer sent me to firewall off the critical propulsion systems.
She tells this to Tilly and Stamets.
Who is that chief engineer? During season 1, I was convinced Stamets is the chief engineer of the ship, but the above statement makes it obvious that someone else holds that position - have we seen him or her, or has their name been mentioned so far?