After finishing high school, she went to a model casting to support a friend, but was instead scouted herself by Stas Yankelevskiy, director of the international division of L-Models agency, who then invited her to Kyiv.

In 2008, she signed a contract with leading modeling agency Women Management in both New York and Milan, and worked with legendary photographer Steven Meisel.

She eventually became one of Meisel's favourite models, with him shooting her for a Calvin Klein Jeans campaign and two Vogue Italia covers (September 2008 and January 2009) amongst others.

[4] Sasonkina has appeared the cover of numerous international magazines, including Marie Claire, Elle, L'Officiel and twice on Vogue Italia.

She has walked for Marc Jacobs, Vivienne Westwood, Bottega Veneta, Missoni, Versace, Phillip Lim, Oscar de la Renta, DKNY, Jason Wu, Prada, Issey Miyake, John Galliano, La Perla, Gianfranco Ferré, Jean Paul Gaultier, Laura Biagiotti, Rodarte, Dior, Michael Kors, Dolce & Gabbana, Roberto Cavalli, Blumarine, Nina Ricci, Anna Sui, Sportmax, Diesel, and Topshop, and appeared in advertising campaigns for Prada, Calvin Klein, Yves Saint Laurent, Alberta Ferretti, Gianfranco Ferré, John Galliano, Liu Jo, Vince Camuto, Mulberry, Sonia Rykiel, Barneys New York, Nordstrom, Juicy Couture, MAC, and Urban Decay.