How Long Do You Think It's Gonna Last? is the second studio album by American indie duo Big Red Machine, which consists of musicians Aaron Dessner and Justin Vernon. It was released on August 27, 2021, via 37d03d and Jagjaguwar record labels. Dessner stated the album is built around themes of childhood, familial dynamics, and mental health. He cited The Last Waltz, the 1978 live album by the Band, as an inspiration for the record.

The album is a collaborative effort featuring guest vocals from an array of artists–Anaïs Mitchell, Taylor Swift, Fleet Foxes, Ilsey, Naeem, Sharon Van Etten, Lisa Hannigan, Shara Nova, La Force, Ben Howard and This Is the Kit. Musically, the record is a mostly slow-paced pop album, consisting of midtempo songs led by soft pianos and guitars, as well as drawing from the indie rock and electronic styles of Dessner and Vernon, respectively. The subject matter covered in the album includes a variety of sombre themes, such as love, loss, grief, nostalgia, reconciliation, and the odyssey of life. Five singles preceded the album: "Latter Days" featuring Mitchell, "The Ghost of Cincinnati", "Renegade" featuring Swift, "Phoenix" featuring Mitchell and Fleet Foxes, and "Mimi" featuring Ilsey. Upon release, How Long Do You Think It's Gonna Last? was met with generally positive comments from music critics, who mostly complimented its melancholic lyrics, stylistic sound, and guest contributions, but cited its frequently monotonous instrumentation as a drawback.