His work is noted for Nikkhil Advani's Lucknow Central film starring Farhan Akhtar directed by Ranjit Tiwari for which Arjuna Harjai composed three songs, background score and the soundtracks for trailers and commercials.

[10] In 2023 he collaborated with Sounds of Isha and various International artists like Machel Montano Marge Blackman and Sandeep Narayan to create the Save Soil and Come Awake anthems for supporting the Save Soil movement by Sadhguru[11] In 2024, Arjuna Harjai launched a creative project titled "The One Minute Composer,"[12] where he composed and released tracks inspired by random prompts, each within a minute-long format.

This series featured songs like "Winter Ayun Waliye," "Mangoge Na," and "Zikar Hai," with the latter being a significant collaboration with Pakistani singer Natasha Noorani.

The project quickly gathered substantial attention, with all three songs making it to Spotify's viral 50 charts, further demonstrating Harjai's ability to resonate with global audience.

[13]"Zikar Hai" was particularly noted for its emotional depth and the innovative cross-border collaboration, which involved remote production sessions between Harjai in the UK and Noorani in Lahore.