The film is based on director Peter Sohn's life with his parents immigrating to the USA from Korea - not speaking English and settling into the Bronx. Sohn's family also opened a grocery store named Sohn's Fruits and Vegetables - similar to Ember's family in the film.
Pixar had to upgrade and buy more computers for this film. There are over 151,000 cores for this film in three large rooms on the Pixar campus. For perspective, Toy Story (1995) had 294 cores, Monsters, Inc. (2001) had 672 cores, and Buscando a Nemo (2003) had 923 cores. This is a massive amount of computing power.
The park Ember and Wade go to, where she changes her color, is shaped like the periodic table of elements.
The film took seven years to make; either with studio space or home space (according to story artist Jason Katz, the story team for the film finished their parts in its creation while working remotely with home space).
A character in the film is named Ghibli, after Studio Ghibli, the renowned Japanese animation studio.