Zendeli was born in Bochum, Germany, to a family with roots in North Macedonia. His father Jauni had fled from North Macedonia before settling in Germany and founding a drywall works company in Bochum. Zendeli began his motorsport career in karting in 2010, competing in German and European championships across the following years. He won the KFJ class of the ADAC Kart Masters in 2014 before concluding his karting career in 2015.
Zendeli made his single-seater debut in the 2016 ADAC Formula 4 season with ADAC Berlin-Brandenburg, finishing 13th overall and fifth in the rookie class. He returned in 2017 with the same team, running a double programme in both the German and Italian Formula 4 championships. He took his first single-seater win at Oschersleben and added further victories at the Nürburgring and Hockenheimring, finishing fourth in the standings.
His breakout came in 2018 when he moved to the US Racing-CHRS team, partnering David Schumacher among others. Zendeli dominated the season from the outset, winning four of the first six races and taking the championship title during the penultimate round at the Nürburgring. He took ten wins from 21 races, claimed eight pole positions from a possible fourteen, and finished more than 100 points ahead of nearest rival Liam Lawson.
Zendeli stepped up to FIA Formula 3 in 2019 with Charouz Racing System. The season proved difficult; his best results came at the Red Bull Ring with eighth and seventh-place finishes, while a puncture while fighting for the lead at Monza denied him a stronger result. He missed the final round and ended 18th with six points.
For 2020 he signed with Trident Racing alongside David Beckmann and Olli Caldwell. After a promising start at the Red Bull Ring, results were inconsistent — he took a podium at the second Red Bull Ring round after charging from sixth to second in a rain-shortened race. His most significant result of the season came at Spa-Francorchamps, where he claimed his first Formula 3 pole position and converted it into a dominant win, leading every lap by a four-second margin. He ended the season eighth in the championship with 104 points, one win, two pole positions, and two podiums, helping Trident to second in the teams' standings.
Zendeli made brief returns to the Formula 3 category in 2022 as a deputising driver, first for Charouz Racing System at Barcelona after a cameo fill-in, and later for Campos Racing at Spa-Francorchamps in Formula 2, replacing the banned Olli Caldwell.
In December 2020, Zendeli was announced as a Formula 2 driver for the 2021 season with MP Motorsport, partnering Richard Verschoor. He scored his first points at the opening Bahrain round with a fastest lap and a ninth-place finish. He added further points at Monaco, Baku, Silverstone, and Monza — including two seventh-place finishes at Monza and Monaco. Financial difficulties cut his season short in early November, and he was replaced by Clément Novalak. He finished 17th overall with 13 points.
After a Super Formula test with B-Max Racing at the end of 2022, Zendeli returned to competition in 2023 in the USF Pro 2000 Championship with TJ Speed Motorsports, competing under the Albanian flag. He made an immediate impact with a fourth-place finish on his debut at St. Petersburg, followed by a podium at Sebring. He scored his first win at Road Atlanta and added further podium finishes at Toronto to accumulate four podiums in total, finishing sixth in the standings with 258 points.
For 2024, Zendeli moved into sportscars full-time, joining Ombra Racing for both the Porsche Supercup and the Porsche Carrera Cup Italia. In the Supercup, he scored points in seven of eight races he entered, with his best result an eighth place at Silverstone, finishing twelfth in the overall standings with 38 points.
In the Carrera Cup Italia, Zendeli showed stronger pace. He claimed a podium on just his second race at Misano with a third-place finish, added another third in Mugello, then secured pole position for the second Imola round. A double podium at Vallelunga capped a competitive campaign, and he ended the season fourth in the overall standings.
Zendeli's trajectory reflects a career marked by strong pace in junior formulae but interrupted by financial pressures and limited budget. His dominant 2018 ADAC Formula 4 title campaign — in which he outscored future Formula 1 driver Liam Lawson by over 100 points — established him as one of the most impressive junior talents of that generation. His subsequent transition to Porsche sportscar competition represented a broadening of his racing portfolio after his single-seater path wound down.