[4][5] On September 16, Baek made her official debut stage on the music program Inkigayo with performances of "Stay" and "Sad Song".

On December 15, Baek released her first original soundtrack "Daddy Long Legs" for the SBS drama Cheongdam-dong Alice.

The song went on to become a sleeper hit, reaching number one on several Korean music real-time charts a month after its release among fierce competition.

[11] "So-so" followed the success of "Shouldn't Have", securing the top spot on all major Korean music charts within a day of its release.

The EP contained six tracks, with the lead single "Sweet Lies" featuring vocal trio The Barberettes.

[16]"The album as a whole, is hypnotic in its pop glory, and lives up to Baek's reputation within Korea as one of the country's most captivating young female soloists.

As a whole, Bittersweet features a wide array of sounds that blend to create an otherworldly listening experience."

- T.H., Billboard[16]Baek A Yeon's fourth EP, Dear Me was released on November 21, 2018, with the lead single "Sorry To Myself" along with five other songs.

[20] On July 13, 2021, Baek A Yeon was supposed to release her fifth EP, Observe, with the lead single "0%", but it was delayed due to rising cases of COVID-19 in Korea.