After starting his career at the age of 12 in 1996, Jani quickly advanced through the karting ranks before moving into single-seaters, becoming Swiss Champion of Formula Lista Junior in his rookie year. He progressed and contested in the Formula Renault 2000 and V6 Eurocup, as well as the GP2 series, before being named as test and third driver for the F1 Scuderia Toro Rosso.
The Swiss driver also competed for A1 Team Switzerland in A1 Grand Prix, helping the team capture the 2007-2008 title and finishing runner-up in 2005-2006 and 2008-2009. In 2007, he raced for PKV Racing in the North American Champ Car series, collecting three podiums and numerous top ten’s in his rookie season.
In 2010, Neel completed his first full season in LMP1 endurance racing, where he teamed up with Nicolas Prost and Rebellion Racing in the European Le Mans Series, achieving two podiums and a third-place finish in the championship. Alongside his full-time sports car ride, Neel continued to honor his commitments with Red Bull Racing, completing simulator and aero testing for the F1 team.
In this testing capacity, Neel completed an aero test in Spain – trying out the newly developed F-duct, and successfully assisted the team in Milton Keynes, with real-time simulator laps on different set-ups to assisting Red Bull drivers Vettel and Webber to qualify P1 and P2 at the Melbourne GP 2010.
Continuing on the momentum of the previous years, 2012 proved to be Jani's most successful season in sportscars. Claiming his first sportscar win at Petit Le Mans he also defeated Audi to take the overall fourth-place finish in the 24 Hours of Le Mans. The 2014 season marked Porsche’s return to the top tier of motorsport and Jani's first year as a Porsche factory driver. He took victory at the 2016 Le Mans 24 hours and as World Champion of the FIA World Endurance with Porsche Motorsport.
After making his Formula E debut with Geox Dragon in the first race of the 2017/18 season, Jani left the series to continue his work with Porsche, focusing on the development of its record-breaking 919 Hybrid Evo. In August 2018, Jani smashed the track record at Spa-Francorchamps behind the wheel of the World Endurance inspired car. Ahead of Porsche's debut season in Formula E, Jani joins the squad alongside Andre Lotterer.