When Marshmello was visiting London in 2017, Anne-Marie popped into the studio to thank him for doing the remix. Her visit produced "Friends," even though she hadn't planned on a session. The English songstress recalled to Billboard
"While he was there, he brought his laptop out and started playing some riffs he had done recently. That little guitar riff you hear in the song - he started playing that, and I was like, 'OK, I need to write a song right now.' We literally wrote it that night, and he worked on it for the next three days in LA, and it was done.
We wrote it to the guitar riff, and it was kind of a Spanish vibe. And then he came back and it was kind of like hip-hoppy - I couldn't believe what he had done to it."