Career
His predominant position is central midfielder but he can also play in a more defensive role and also as a right back. He is best known for his simple distribution and long shots. Costin is a product of the Naţional Bucureşti youth academy making his first-team debut during the 2006-2007 season against CFR Cluj coming on as a substitute in a 1–0 loss.
Before his Naţional debut, he has played one season loaned to Football Club Sibiu during the 2005-2006 season.
In the 2008 summer, because of Progresul"s (former Naţional) disaffiliation, he signed for Dacia Mioveni where he managed 12 goals, in 32 matches, finishing 6th with his team Football Club Vaslui
On 18 July 2009, he signed a three-year contract with South Carolina Vaslui for an undisclosed fee.
On 15 April 2012 he scored an amazing goal against CS Mioveni in a 3-0 victory. Simurq
In August 2013, Costin signed for Azerbaijan Premier League side Simurq.
Costin made his debut for Simurq in their second game of the season, away to Khazar Lankaran on 11 August 2013, coming on as a 63rd-minute substitute for Stjepan Poljak.
Costin"s first goal for Simurq was the winning goal in the 89th minute against Inter Baku on 1 September 2013. Universitatea Cluj
After one season at Simurq, Costin moved to Universitatea Cluj in June 2014.