Mia Hansen-Løve wrote this script during the winter of 2019-2020. She was partly inspired by her father's illness while he was still alive. In her own words, she was trying to make sense of what she was going through. And she wanted to explore how two opposing feelings, a sense of grief and rebirth, can dialogue, experiencing them simultaneously.
For Mia Hansen-Løve, the film is "the story of what it's like being in mourning for someone who's still alive."
According to herself, Mia Hansen-Løve chose Pascal Greggory for the role of Georg because of his elegance, his restraint, his sensitivity, and a disturbing physical resemblance to her father.
The piano theme that is heard several times in the film is Jan Johansson's "Liksom en herdinna" ("Like a Shepherdess"). It was also the piece that accompanied Mia Hansen-Løve as she prepared the film. What makes this piece special for her is that she discovered it in an Ingmar Bergman film, El toque (1971), which talks about an adulterous passion between two characters played by Bibi Andersson and Elliott Gould.
Mia Hansen-Løve wrote the role of Sandra with Léa Seydoux in mind. But Hansen-Løve wanted to strip Seydoux, who she called "super-sexy with incredible magnetism," of her glamour and portray her as more real and raw so viewers could see deep inside her, beneath her exterior. To do that, the director had Seydoux wear casual clothes and have short hair.