David realized his first project at the age of 17. In 2014, his debut feature film "Adam" premiered with Pia Hierzegger, Wolfram Berger and Reinhard Nowak in Austrian cinemas.

After a large number of festival participations, he won the Diagonale Prize for best short film for his film "Cornetto im Gras" in 2023. With this film, Lapuch was nominated for the Austrian Film Award 2024 in the category "Best Short Film".

In 2023 he was part of the "exp:an:ded shorts" jury at the This Human World Festival for International Human Rights.

In 2024 he was a member of the national and international jury of the Filmfestival Kitzbühel.

Since 2024 he has been a member of the Film Advisory Board of the Federal Ministry for Art, Culture, Public Service and Sport Austria (BMKÖS).

He is also a member of the Academy of Austrian Film and the Austrian Screenplay Association.