Teaching assistants (TAs) play an integral role in teaching computer science undergraduates in North America. We report lessons in lab TA management, based on a case study which identified environmental factors affecting TAs' job satisfaction. These factors were identified through a series of semi-structured interviews about 23 lab sections taught at the University of British Columbia. We corroborated this with observational sampling of eight different TAs. Identified physical factors affecting job satisfaction include the layout and lighting of the lab rooms. Temporal factors include the intensity and length of the lab sessions. Having a positive social environment (in particular, support from team teaching and staff meetings) was also found to improve job satisfaction.