Born in Venlo, Janse began playing football with amateur team MVC '19 from Maasbree, the town where he grew up. When he became older, he began playing for the youth teams of VVV-Venlo, the biggest club in the city where he was born. He was soon spotted by PSV Eindhoven. In PSV's youth, he played as a right winger, but after taking the advice of skills- and talent coach Ricardo Moniz, he instead began playing as a right back. After playing great as a right back, PSV wanted to offer him a first team contract, but because of the presence of Kasper Bøgelund, Michael Lamey, André Ooijer and Michael Reiziger, he was advised to play somewhere else. Willem II showed their interest, and Janse decided to play in Tilburg.
Willem II
Janse was chosen to play for Willem II's first team at the beginning of the 2005–06 season. On 11 January 2006, Janse made his debut under the leadership of coach Kees Zwamborn in the match against Heracles Almelo. The match ended in a 1–2 defeat for the Tricolores. Janse profiled himself by making an assist, and getting a yellow card.[1] In this season, Janse played in 8 more matches.
Despite his good entrance in the Eredivisie for Willem II, it took a long time until he played again. Although, the 2006–07 season was marked as the great breakthrough of Janse. When his biggest competitor, Nuelson Wau, became injured, the road was paved for a fantastic season for Janse. Often he was the only bright spot for the chaos characterized club. Because of his good performances for Willem II, his competitor Wau eventually signed with Roda JC.
On 24 January 2009, Janse made his first goal in the league in the away match against Feyenoord (1–1).[2]
Janse signed with Willem II's rivals, NAC Breda on 8 April 2010 and he will join the side after the 2009-10 season.[3][4]
On 15 February 2014, Janse signed a contract with Dinamo Tbilisi.[5]
Ternana
On 5 September 2014, Janse signed a contract with Ternana Calcio.
Leyton Orient
On 20 September 2016 it was announced that Janse was joining Leyton Orient till the end of the 2016–17 season. He was sent off 14 minutes into his debut against Plymouth Argyle.
Italy
After a season at VVV-Venlo, Janse moved to Italy in September 2018 and joined the newly promoted Eccellenza amateur club Ellera Calcio.[6] In December 2018, he then moved to Serie D club A.C.R. Messina.[7]
Janse played 12 games in Messina, before returning to Ellera ahead of the 2019-20 season.[8] On 28 August 2020, Janse joined FC Viterbo in the Italian Promozione.[9]