Paul Mazursky was nominated for Best Supporting Actor for his performance in this film. He directed himself.
This is thd first time Ellen Burstyn was credited as Ellen Burstyn instead of Ellen McCrea or Ellen MacCrea.
Although not biographical, Alex's character was probably based on Mazursky's fellow director Hal Ashby.
Ellen Burstyn's first film directed by Paul Mazursky. Her second was 'Harry & Tonto' (1974).
At the beginning of the film the camera angles hide which studio Alex pulls into, but the Irving Thalberg Building indicates that it's MGM.