Kari started karting in 2009 and took part in his first race in 2010. He raced in several national karting series in Finland from 2010 to 2013. In 2014, Kari moved to KF European where he finished fifth overall.[2]
Junior formulae
Kari moved to single-seaters in 2015, starting in the new SMP F4 Championship. He won seven races and took the title with three races to spare. Kari moved to European Formula 3 Championship in 2016 with Motopark.[3] He took victory at the first race at Imola after a late lunge on Lance Stroll and finished fifth in the rookie standings and tenth overall.
GP3 Series and Formula 3
2016
In August 2016, Kari was also announced to take part in the GP3 rounds at Spa-Francorchamps with Koiranen GP, in place of Ralph Boschung.[4] He retired from the first race, and finished 14th in the second, scoring no points.
2017
In November 2016, Helmut Marko confirmed Kari would move to the series full-time in 2017.[5] In January, Kari was signed to Arden International.[6] Kari finished the season with one race victory, one third place finish, 63 points and 10th place in drivers' championship. He was dropped from the Red Bull Junior Team after the season.[7]
2018
Kari continued to race in GP3 switching to MP Motorsport for the 2018 campaign.[8] After 14 races into the season Kari was promoted to FIA Formula 2 Championship with MP Motorsport for the remainder of the 2018 season.[9] As a result, Kari finished the season with three point scoring finishes, six total points, and a 17th place in the drivers' championship.
2019
For the rebranded 2019 F3 season, Kari would drive for Trident, and he would achieve two podiums, both 3rd place finished, in Barcelona and Sochi. He finished 12th in the championship with 36 points.
In December 2015, Kari, along with his Motopark teammate Sérgio Sette Câmara, became a member of the Red Bull Junior Team and thus becoming a test driver of Scuderia Toro Rosso. In November 2016, it was confirmed Kari would remain a part of the Junior team.[10] In August of the following year, Kari was dismissed from the program.[7]
^"Onko tässä Suomen seuraava F1-kuljettaja? (Is this the next Finnish F1 driver?)". November 26, 2016. Retrieved November 26, 2016. Formula 3:n eurosarjassa Kari oli tällä kaudella vasta kymmenes voitettuaan 30 startista vain yhden, mutta ensi kaudella Kari saa paikan GP3-sarjasta. Asian vahvisti MTV Sportille Red Bullin moottoriurheilupomo Helmut Marko (Formula 3 Euro Series Kari was only tenth in this season after winning just one of 30 start-up, but the next season Kari gets a seat in the GP3 series. This interest was confirmed by MTV Intersport in Red Bull's motorsport boss Helmut Marko).
