In Transformers: Dark of the Moon, the character known as Engineer is a human employed by NASA. His full name, according to the film's novelization, is Bob Singer, though he is credited simply as Engineer in the movie itself. He lives with his wife, Julia, and his daughter, Madeline.

In the story, Engineer is depicted as someone who became complicit in a significant cover-up. He assisted the Decepticons in concealing the true nature of the events that transpired on the Moon, a secret that forms the central conflict of the film. His role, though brief, reveals a hidden history within NASA and sets a small but important part of the film's conspiracy in motion.

The character is killed in his own home by Laserbeak, a Decepticon operative, when he expresses a desire to understand what is happening. This event demonstrates the ruthlessness of the Decepticons and their willingness to eliminate anyone who knows too much. Engineer does not have any notable abilities beyond his professional expertise, and his development is limited to this single, fatal encounter. His primary significance in the narrative is to illustrate the long-term and clandestine Decepticon infiltration of human institutions.