All the VFX for this film were done by 9 people, including the two directors, with the majority of the shots being done by a core group of 5 people. None of the VFX team went to school for VFX. They were all friends who taught themselves with tutorials they found online for free.
To keep plot details under wraps before the trailer was released, the IMDb synopsis read, "It's about a 55-year-old Chinese woman trying to finish her taxes."
Michelle Yeoh said that the film was completely out of her comfort zone, "I was suddenly doing comedy, physical comedy, action, horror, every single genre all packed into one, and jumping in and out of it. It was such a gratifying experience. I've waited a long time to receive a script like that. Because, as you get older, the box gets smaller and smaller."
Evelyn speaks to her father in Cantonese, but she speaks to Waymond in Mandarin, showing cultural differences in their upbringing. Evelyn speaks to Joy in Mandarin and English, while Joy answers back in English and bad Chinese. Neither one finds the words to express their ideas clearly to the other, keeping them divided.
Ke Huy Quan's first major role in 20 years, since Mou han fou wut (2002). He had a minor role in 'Ohana ou le trésor caché (2021). This marks the second-longest hiatus in an acting career before winning an Academy Award. The longest belongs to George Burns, who won for Ennemis comme avant (1975), his first major role in 36 years, since Honolulu (1939). The record for longest hiatus before a nomination belongs to Gloria Stuart, who was nominated for Titanic (1997), her first major role in 51 years, since She Wrote the Book (1946).