Rubik was born in Rzeszow, Poland. In 1988 she and her family moved to Greece. They later moved to Canada and to Umtata, South Africa. Among the schools she attended was one in Czestochowa, Poland. Rubik was introduced to modeling while attending a British high school in Paris. She wanted to finish her schooling before officially becoming a model, and so only worked on school holidays. Her mother, father and sister still reside in Poland.
Vogue Paris declared Rubik one of the top 30 models of the 2000s. As of May 2010, she is ranked 3rd, behind Natasha Poly and Lara Stone, on the Top 50 Models Women list and 18th on the Top 25 Money Girls list, which ranks the highest earning high fashion models in the industry, by models.com. As of September 2012, she is ranked as an icon.
Rubik is featured in the 2009 fitness video game Yoga Wii for the Wii home console. She was also an inspiration for a character in the manga "The One" as the main character Cane Lele.
Since 2010, she has appeared on Top Model. Zostan modelka, the Polish edition of America's Next Top Model.
Rubik is featured in the 2011 Pirelli Calendar photographed by Karl Lagerfeld. She was one of the models to star in Lacoste's "new look" campaign in January, a different advertising concept for 2011 under the new tagline, "Unconventional Chic". The ads were shot by Mert and Marcus, showing models wearing the iconic white Lacoste polo shirts worn over fancy black evening wear. Rubik renewed her contract with Fendi for the third season in a row. In 2013 she was ranked third on Vogue's "Top 10 Models of 2013" list. In 2014 she became the host and a judge of the Polish version of the reality show Project Runway TVN.
She is a favourite model of Karl Lagerfeld.
In 2012, Rubik founded and created 25 Magazine. Contributors include Inez and Vinoodh, Marina Abramovic, Nobuyoshi Araki, Daniel Arsham, Paola Kudacki, Alex Prager, Hedi Slimane, Isabel Marant and Yoann Lemoine. In September 2015, Rubik made her directorial debut by directing Issue 04's teaser film featuring Andreea Diaconu and themed around the power and impact of the five senses.
In 2014, Rubik starred in a music video for the song Chleb by Mister D., a music project of the Polish author Dorota Maslowska.
Rubik and her longtime boyfriend, Serbian model Sasha Knezevic, became engaged just before Christmas 2010 in Vienna. They married on 16 July 2011 in Deia, Majorca.