Managerial Staff

Çağatay Ölken began his career in 2006, working at various leading international banks, undertaking roles in project finance and investment banking. From 2011 to 2017, he served as Director responsible for investments at a private equity fund and held various management and board positions in domestic and international portfolio companies.

In 2017, he joined Koç Holding as Energy Group strategic planning coordinator and later in 2019, he joined Tüpraş as Senior Director of Strategy and Sustainability, contributing to the company's long-term transformation and investments.

As of 1 February 2026, he has been appointed as General Manager at Ditaş Tankers.

He completed his double major degrees in Mathematics and Business Administration at Koç University.

He is fluent in English.

Osman Mehmet Mutlay graduated from the Department of Economics at Bilkent University in 2004 and successfully completed the Executive MBA program at Koç University in 2017.

He began his professional career in 2006 as a Cost Accounting Specialist at Arçelik A.Ş., and held various managerial positions in the Procurement, Financial Reporting & Integration, and Finance departments until 2019. Between 2013 and 2015, he was assigned to Defy Appliances, Arçelik A.Ş.'s subsidiary in South Africa, where he led the execution of Financial Reporting and Integration processes at a global level.

From 2019 to 2025, he served as the Director of Finance and Accounting at Arçelik LG Klima Sanayi ve Ticaret A.Ş., where he was responsible for overseeing the company's financial operations, as well as strategic planning and budgeting.

As of May 1, 2025, he continues his career as Deputy General Manager for Financial Affairs (CFO) at Ditaş Tankers.

He is fluent in English.

Numan Eşiyok graduated from Istanbul Technical University, Faculty of Maritime Studies, Department of Deck in 1997 and completed his master's degree in Marine Transportation Management at the Institute of Natural and Applied Sciences, Department of Marine Transportation Engineering at the same university in 2020. 

Mr. Eşiyok started his professional career in 1997 and worked as Deck Officer, 1st Officer and Captain in various maritime companies until 2005. In the same year, he started to work as Deck Inspector at Ditaş Deniz İşletmeciliği Ve Tankerciliği A.Ş. and has assumed many different duties and roles until today. 

Mr. Eşiyok, who is currently serving as a Member of the Assembly and Vice President of the Assembly of IMEAK DTO Aliağa Branch, has been working as Assistant General Manager at Ditaş Deniz İşletmeciliği ve Tankerciliği as of October 1, 2020.

Onur Önyılmaz graduated from Middle East Technical University, Department of Mathematics in 2007.  

He started his professional career at Tüpraş Finance Department in 2008. Afterwards, he assumed various managerial roles in Foreign Trade Finance, Financial Reporting, Hampetrol Supply and Logistics Optimization departments of the same company. 

As of the October 4, 2021, Mr. Önyılmaz has been serving as the Commercial Director at Ditaş Deniz İşletmeciliği ve Tankerciliği.

He speaks English fluently.

Elif Topçu began her professional career in 2005 as a Production Engineer at Hugo Boss. In 2008, she joined BSH - Bosch and Siemens Home Appliances Group, where she held various roles across project management, production systems, and human resources processes. In the early stages of her career, she gained extensive experience in production, project, and process management, later specializing in Human Resources Management and Organizational Development.

In 2019, Topçu joined Koç Group and assumed several managerial roles at Tüpraş, focusing on corporate culture, agile transformation, organizational development, and corporate learning. As of 2023, she served as Academy and Agile Transformation Director, leading the establishment of the corporate academy structure and the implementation of comprehensive development programs.

As of February 1, 2026, she serves as Human Resources and Corporate Communications Director at Ditaş Tankers.

Topçu holds a Bachelor's degree in Industrial Engineering from Balıkesir University and is fluent in English.

İbrahim Bayraktar, graduated from the Department of Mechanical Engineering at Boğaziçi University in 2005 and completed his master's degree in 2015 through the Executive MBA program at Sabancı University.

He began his professional career in 2007 in the Product Development Department at Ford Otosan, where he later took on various roles and responsibilities within the same company.

As of August 22,2023, he continues to serve as the Strategy, Investments and Sustainability Manager at Ditaş Deniz İşletmeciliği ve Tankerciliği.

He is proficient in English.

After graduating from Marmara University Faculty of Law in 2005, Halide Solmaz started her professional career by registering to the Istanbul Bar Association. Until 2010, she worked as a lawyer in various law offices.

In 2010, she joined Koç Group by starting to work as a lawyer at Koçtaş Yapı Marketleri Ticaret A.Ş.

In 2012, she started working as a lawyer at Ditaş Deniz İşletmeciliği ve Tankerciliği A.Ş. and continues to work as Legal and Compliance Counselor. She specializes in Commercial Law, Corporate Law, Maritime Commercial Law and Maritime Labor Law.

In 2014, she completed her Master's Degree in Private Law at Marmara University Institute of Social Sciences and is fluent in English.

Can Tüfekçi graduated from Karadeniz Technical University, Department of Finance, in 2010, and completed his Master's degree in Accounting Auditing at Marmara University in 2013.

He obtained the Capital Markets Board Independent Audit license in 2012, the Certified Public Accountant (CPA) license in 2014, and the Public Oversight Authority Independent Auditor license in 2015.

He began his professional career in 2011 as an Assistant Auditor, conducting independent audit engagements for both national and international companies. In 2016, he joined Setur, a Koç Group company, as an internal auditor. In 2018, he assumed various roles at Tüpraş in internal audit, risk management, and non-fuel product sales teams.

As of May 2025, he continues his career as Internal Audit Manager at Ditaş Tankers.