[6] The following day, a credits poster was unveiled revealing that Somi was involved in the songs's writing and production as well.

[9] "What You Waiting For" was written by Teddy, R.Tee, 24, Jeon Somi, Danny Chung and produced by Teddy, R. Tee, 24[7] The final version was fully recorded at The Black Label in Seoul, South Korea in February 2020, five months before the release, on July 22 of the same year.

[10] It is an upbeat R&B, dance-pop,[1] synth-pop,[2] electronica and power-pop track[3] that incorporate elements of trop-house, EDM-pop,[11] moombahton and 2010s house beats.

[12] The track built around an "emotional" chord progression that contrasts with "the bright" synth sound, which is considered different from somi's previous songs.

[13][14] The track "opens with a subtle synth-pop production, bouncing through DIY-vibe electronica and a racing, power-pop chorus as Somi tells an apprehensive lover 'Baby, I’ve been waiting for you all this time!".

[15] In an interview, Somi claimed the song had no specific inspiration, adding that it might have been "the late night tacos and chicken wings" she and her producers had been waiting for.