Mag. Machac is a self-employed lawyer and runs a law firm for criminal matters in Vienna with a focus on offenses against physical integrity, sexual criminal law and narcotic substances law.

He is one of the leading experts on the Austrian Narcotic Substances Act and author of the book "Addictive Substances Law for Practice". Before studying law, he worked in gastronomy and passed the university entrance exam. After studying in Oslo and Vilnius, he worked for the public prosecutor's office in Vienna and completed additional training as a mediator.