[1] During his upbringing in Bulgaria, Kostadinov's only exposure to arts and culture was receiving clothes from his uncle who resided in London.
He initially enrolled in a foundation course at London College of Fashion, but realized he wanted to attend Central Saint Martins.
After being rejected from Central Saint Martins, Kostadinov would assist a number of menswear designers and stylists, such as Aitor Throup, Nicola Formichetti, and Stephan Mann.
During his education, Kostadinov created commission pieces made from Stüssy clothing for an editorial featured in Clash magazine.
Although the clothing was bespoke and never intended to be sold, Stüssy reached out to him to collaborate on a capsule collection to celebrate their 35th anniversary in 2015.
[8] In January 2017, he presented his debut collection, characterized by meticulously engineered garments with highly functional cuts and finishes.
[12] In the fall of 2018, Kostadinov introduced a womenswear line to be led by Laura and Deanna Fanning, who had graduated from Central Saint Martins' master program 7 months prior.
[17] The instillation featured coats and bags that drew from Kostadinov's Bulgarian heritage and the workwear of his father's profession.
The instillation led to the creation of a collaborative diffusion label, Otto 958 (slightly altering the original exhibit's title).
[22] The interior of the store would be designed in collaboration with award-winning Japanese architect, Yusuke Seki, and experimental filmmaker, Ryan Trecartin.
[26] The collection featured motocross-inspired jackets, hoodies, long sleeves, jerseys, balaclavas, and racing gloves.