On 31 January 2016, Justs was announced as one of the 20 competing acts in the second season of Supernova, the show used to select Latvia's representative to the Eurovision Song Contest.

[5] On 28 February, he won the national final and then represented Latvia at the Eurovision Song Contest 2016 in Stockholm, Sweden.

In September 2018, Sirmais announced on Instagram that he would be studying Music Production at university in Bristol, United Kingdom.

[11] In November 2020, Sirmais participated in the first season of Balss Maskā as the cute "Sparrow" and placed 3rd.

On 20 November 2024, it was announced that Sirmais was selected as a semi-finalist in Supernova 2025 with the song "Fit Right.