[1] In 2008, he was accepted into the Estonian Academy of Music and Theatre's (EMTA) School of Performing Arts Department in Tallinn and studied under course supervisor Elmo Nüganen, graduating in 2012.

Among his more notable roles to date at the theatre were in productions of works by Peter Barnes, Molière, A. H. Tammsaare, Tom Stoppard, Ferenc Molnár, John Steinbeck, Otfried Preußler, Rodney Ackland, Marina Carr, Michael Cristofer, William Shakespeare, Duncan Macmillan, Anton Chekhov, August Strindberg, Eduard Bornhöhe, Daniel Glattauer, August Gailit, Paavo Piik, and Diana Leesalu.

The same year, he was cast in a starring role of Karl Tammik in the feature-length war drama 1944, directed by former Estonian Academy of Music and Theatre course supervisor Elmo Nüganen.

In 2018, he was cast in a starring role as Igor in the Ari Alexander Ergis Magnússon directed Icelandic-Estonian coproduction drama film Mihkel, opposite actors Tómas Lemarquis, Pääru Oja, and Atli Rafn Sigurðsson.

In 2020, he appeared in a small role as a police operator in the Christopher Nolan directed Warner Bros. Pictures English-language science fiction action thriller Tenet, which was filmed, in part, in Estonia.

In 2021, he appeared as Pilot Selenov in the English-language period romantic drama Firebird, directed by Estonian Peeter Rebane, and filmed on location in Estonia.

[11][12] In 2013, Velberg made his television debut as the character Kristjan Malman on an episode of the popular, long-running TV3 comedy-crime series Kättemaksukontor.

[8] In 2021, he played a starring role as Mark in the six-part miniseries thriller Tulejoonel, directed by Ergo Kuld and penned by Martin Algus.