[13] Johnson co-wrote and produced Harry Styles' 2017 debut self-titled solo album,[4] the 2019 follow-up Fine Line,[14] including "Watermelon Sugar",[15] which went to number one on the Billboard Hot 100,[16] Styles' third studio album, Harry's House, which won a Grammy Award for Album of the Year at the 65th Annual Grammy Awards, and its lead single, "As It Was", which spent 15 non-consecutive weeks at number one on the Billboard Hot 100 and was the best-selling global single of 2022.

Johnson won a Grammy Award for Record of the Year for producing Miley Cyrus's 2023 single "Flowers",[2] which spent 8 weeks at number 1 on the Billboard Hot 100.

[2] In 2024, Johnson co-wrote and co-produced two songs ("Amen" and "Ameriican Requiem") on Beyoncé's Grammy-nominated album Cowboy Carter.

[18] He also wrote and produced on Halsey's album The Great Impersonator[19] and Childish Gambino's Bando Stone & the New World.

[20] As a writer, producer, and engineer, Johnson has also worked with artists including Keith Urban, John Legend, Diplo, Pink, OneRepublic, Sam Smith, Meghan Trainor, Toni Braxton, 070 Shake, and Leon Bridges.