Wastyn started with sports at a young age. He soon focussed on cycling. In 2010 Wastyn rode as a junior in the World championship of cycling in service of Jasper Stuyven, who took the bronze medal. During the time at Ghent University, he rode for Jong Vlaanderen-Bauknecht. Until he went to Verandas Willems during his final year at university.
2015
After Wastyn obtained his master's degree in industrial engineering he could fully focus on cycling. In 2015 he rode his second year for Verandas Willems and managed to ride some nice results. His most important result was a victory in Izegem Koerse; he won the sprint and finished before Michael Van Staeyen and Timothy Dupont.
2016
After a promising year, where Wastyn showed to have the potential, he eventually signed for the Irish cycling team An Post–Chain Reaction. With his new team he showed to have a pair of fast legs. He is often used as a lead out for one of his fast teammates. But he also manages to ride some good results too. In GP Criquielion he finished 4th. In An Post Ras he finished 4 times in the top 10, got a fifth place for the Green jersey in the sprint. As a lead out in the sprint he helped his teammate Aaron Gate to a second consecutive green jersey.