The New York Times has a great article on Anomalisa. It's similar to the other how-Anomalisa-went-from-stage-to-screen articles I've posted, but there are some good quotes and other little nuggets that make this one worth reading.

“Looking at it in retrospect,” Mr. Kaufman said, “it seemed like it was meant to happen. But while you’re going through it, it’s like: This is never going to happen. This is never going to happen. This is never going to happen.”

[...]

“Charlie is a very quiet, shy, slightly dour person,” Mr. Stamatopoulos said. “I’ll call Charlie up and say, ‘Hey, how ya doin’?’ And he’ll be like, ‘Eh, not so good,’ and I’ll be like, ‘Oh, he’s having a good day.’ ”

[...]

“I love doing stop-motion for no reason except that it’s stop-motion,” Mr. Stamatopoulos said. “My favorite thing is a puppet not moving, just sitting there and being depressed.”

[...]

Mr. Johnson and Mr. Kaufman had to remain in constant communication. The directors estimate that no more than 15 to 20 animators worked on the film at a time, each of whom, at best, produced about two seconds of footage a day.

“Over the course of time, people come and go,” Mr. Johnson explained

Mr. Kaufman added: “People died. People were born.” (Source)

Additional information