He attended Tallinn Old Town Educational College (VHK) and is a 2008 graduate of the Estonian Academy of Music and Theatre.

[3] In 2012, he appeared onstage as an actor and singer in the role of Aadu in the children's play Kosmonaut Lotte at the Vanemuine theatre in Tartu.

Haasma is possibly best recalled through his television appearances, however, as a regular cast member on the TV3 comedy-crime series Kättemaksukontor, in which he played the role of Rainis Sõber in over eighty episodes from 2013 until 2018.

Haasma's impersonations included Macy Gray, Jan Uuspõld of the Luxury Filters, Amy Winehouse, Kiesza, Helend Peep, Bruno Mars, and Angus Young of AC/DC, among others.

[6][7] Juss Haasma made his feature-film screen debut in a small role in 2007 as an Estonian Army soldier in the Andres Maimik and Rain Tolk directed road movie comedy Jan Uuspõld läheb Tartusse; a film that portrays Estonian actor and singer Jan Uuspõld as a down-on-his-luck caricature of himself trying to hitchhike from Tallinn to Tartu to perform in a role at the Vanemuine theatre.

In 2012, he played the character Otto in the Ain Mäeots directed drama Deemonid; which focuses on the downward spiral of three individuals who enter a casino.