Joe Alwyn is credited as a co-producer of Taylor Swift’s “august.”
The song’s production credits list Swift, Jack Antonoff, and Alwyn. Antonoff built the initial instrumental, while Swift wrote the lyrics and contributed to the finished recording. Alwyn’s credit reflects his studio involvement during the making of Folklore.
Alwyn also worked on Folklore and Evermore under the pseudonym William Bowery. That name appears in songwriting and production credits, so it is easy to treat William Bowery and Joe Alwyn as two different collaborators. They are the same person, but the “august” article identifies Alwyn directly in its production information.
Aaron Dessner is another prominent Folklore producer, though he is not the answer to this particular credit question. Dessner’s extensive work on the album is one reason fans sometimes attribute every Folklore production credit to him.