The song was produced by No I.D., who is best known for working with hip-hop artists such as J. Cole, Big Sean and Jay-Z. When Cara first got together to make music with the Chicago beatmaker she had the title and some of the lyrics for "Comfortable," while he had the instrumental partially finished. This differed from the way the Canadian usually approaches her songwriting. She explained to Vulture
"I usually have a song finished when I go into the studio and have a melody and chords. But with this song, I just had lyrics. I didn't even know what I wanted it to sound like."
No I.D. started playing Cara a bunch of instrumental demos. The Canadian noticed he had one file titled "doo-wop" which attracted her attention. When he played it for her she immediately loved it. "I thought it was so interesting," she recalled. "It was super rough at the time but it was very reminiscent of the old Motown music that I grew up listening to."
Cara took No I.D's "doo-wop" beat to the hotel with her and started to write it. When she pulled up the lyrics to "Comfortable" and started singing them over the melody the songstress found it worked perfectly.