Solely produced by the duo, the album features guest appearances from Matthew Young, Age.Sex.Location, Stevan, and Ruel.

Yesteryear was a critical and commercial success, peaking at number 42 on the ARIA Albums Chart and receiving a nomination for Best Dance Release at the 2021 ARIA Music Awards.

[7] Upon release, the duo said "It's an album inspired by personal growth, looking back on these experiences, learning from them and moving forward with optimism.

[9] Jake Cleland from Stack Magazine said "Their second album shows more mature songwriting and a stronger sense of self, but nostalgia for the past.

"[10] Sose Fuamoli from Triple J called the album "a sophisticated and well-engineered collection of music, showing that even though they spent a lot of Yesteryear's creative process reflecting and looking back, Cosmo's Midnight's future has never been brighter.