[1] Goundoulakis started playing professional football in 2000–01 at Kalamata F.C.In January 2004 he was transferred to Panionios and immediately got the basic position in the first team squad.
He was a key member of the team during seasons (2006–07 and 2007–08) when they finished fifth in the championship with coach Ewald Lienen and participated in UEFA Cup and Intertoto Cup.
It may not have frequent contact with the nets, but was especially dear to a purple platform because of militancy.
In 2007, in an away match of the UEFA Cup group, achieved an amazing goal on Helsingborgs (score: 1–1), which is still remembered by fans of the club.
On 26 April 2016, Platanias officially announced the extension of experienced attacking midfielder' contract until the end of next season.