Member of Chartered Institute of Arbitrators, Chartered Institute of Building,The Academy of Experts, Turkish Chamber of Civil Engineers, Dispute Board Federation, Dispute Resolution Board Foundation and Society of Construction Law. Mr Sonbahar is a graduate of MSc Construction Management and Engineering, University of Reading.

Mr Sonbahar provides expertise in international construction arbitration cases, management of contracts, claims and disputes, planning, delay analysis, quantum and cost control. Mr Sonbahar has recently participated in several construction disputes and arbitration cases concerning projects financed by EBRD, Asian Development Bank, JBIC and Word Bank in respect of highways, light railways, residential buildings and shopping malls , army camps, water distribution projects; in Turkey and also worldwide including Europe, Middle East and CIS Countries. Mr Sonbahar has been involved in a number of international disputes acted under the different institutions including UNCITRAL, ICC and DIAC.