What advice would you give to a Greek Civil Engineer (15 years experience) who wants his next career step to be in the Middle East?

Dear Nik,

If you are a Bachelor in Technology in civil or Bachelor in Engineering in civil then you can positively apply in Middle East companies.

If You are a diploma in Civil then you must consider doing B.E or B.tech. 

Once you have an offer from any company from Middle east then accept only Engineering visa. Don't accept any other visa(i mean it). 

With Engineer visa you have a special status here in Govt. offices/ Airport etc.