[7] She started taking ballet lessons when she was three years old, and continued her training at Broadway Dance Center in New York City while competing nationally.

[15] In 2013, while a junior at university, Kostek made it to the roster of the National Football League's (NFL) New England Patriots Cheerleaders.

[19][20] Kostek was featured in advertising campaigns for Patriot Place,[21][non-primary source needed] and served as spokesperson for the cheer team in various television shows and public engagements.

[22][23] In her last game before retirement, she performed at the University of Phoenix Stadium in Arizona for Super Bowl XLIX where the Patriots beat the Seattle Seahawks on February 1, 2015.

[30][31] Out of college, Kostek was offered a job on ESPN's Saturday Night Football, but turned it down for the opportunity to travel while modeling.

Kostek initially found difficulty securing modeling representation as agencies kept telling her she was not tall enough at 5'8", or thin enough at dress size 4/6.

[64][65][66] Kostek was chosen from 5,000 open casting call candidates and won the inaugural Sports Illustrated Swim Search in March 2018.

[68] The first model announced for the 2019 issue, Kostek shot in South Australia with photographer Josie Clough, and landed a solo cover in her official year as a rookie.

[74] Kostek made her film debut with a cameo appearance in STX Entertainment's 2018 comedy I Feel Pretty starring Amy Schumer.

[77][78] In 2020, she released a clothing and accessory collection inspired by her trademark phrase "Never Not Dancing" with Shine the Light On, proceeds of which benefit mental health charities.