Chmielarz's career started in early nineties, when he founded his first company called Metropolis with money earned selling not-always-legal games and programs. It wasn't a software business at first, primarily dealing with hardware and PC parts. It was shortly after communism fell and big players in hardware world started emerging in Poland, so Chmielarz had to pursue other options. This lead to creation of his first game - Tajemnica Statuetki (roughly translates to 'Secret of the Statue') in 1993. With 5 thousand copies sold, it was a huge success, given early nineteens state of the market in Poland.
Two years later, followed by big marketing campaign Metropolis released their second adventure game - Teenagent. This is also the first game to be released outside Poland and translated to other languages. Metropolis kept making games, but Chmielarz decided to leave the company and his former high school friend in 2002. After short period of work as a consultant Adrian co-founded new studio - People Can Fly. Painkiller was the first game made under new banner. Sales were not great, but PCF made their impact and begin working on the sequel. In 2007 Epic Games bought a majority stake of shares in People Can Fly and provided expertise and distribution for PC conversion of Gears of War in 2007 and Bulletstorm in 2011.
In August 2012, Adrian Chmielarz left People Can Fly and sold his remaining shares to Epic Games.