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Management Team

Yucel Karadeniz

General Manager

He started his career as a Software Engineer at NETAŞ R&D in 1988. Having completed 11 years of NETAŞ working life as Software Department Manager, Yucel Karadeniz has managed the value-added service world and Turkcell R&D as a senior manager at Turkcell Group between 1999 and 2006. He continued his responsibility as the Assistant General Manager responsible for Product Development of Turkcell Technology, which he was among the founders of, between 2007-2013.

Serving as Assistant General Manager responsible for Technology and Operations at E-Kent company between 2014 and 2015, Yucel Karadeniz has carried out the development and management of Integrated Smart City, Smart Transportation, Smart Sports and E-Ticket technologies and solutions offering infrastructure transformations, efficient service operations and new revenue sources to municipalities and public institutions in 23 cities.

Karadeniz, who has undertaken the management of the consultancy team under the umbrella of IBM Global Business Services between 2016 and 2017, has held the position of Executive Board Member and Deputy Chief Technology Officer at ETSTUR between 2018 and 2019.

Karadeniz, who served as the General Manager of BELBİM Inc. between 2019-2021, was assigned as the General Manager of ISTTELKOM Inc. as of December 1, 2021.

He is married with one daughter and speaks English.

Nesegul Yardimciel

Finance Manager

Nesegül YARDIMCIEL was born in Istanbul and graduated from Fatih Commerce High School and completed her undergraduate education in Anadolu University, Faculty of Economics, Department of Finance in 1997. She continued her education at the International Janus University, Department of Business Administration” followed with a higher certificate program in “Finance & Financial Services” at BBSI in the United Kingdom in 2008.

She worked as Accounting Manager at Mondial Assistance company of ALLIANZ Group between 1997-2007, and as Tax Leader, Controller, Finance Manager at GENERAL ELECTRIC between 2010-2017. She worked as the Accounting-Treasury Leader at KPMG Turkey Head Office between 2018-2021.

Yardimciel started to work at ISTTELKOM Inc. in November 2021 and continues to work as Manager Financial Affairs.

Nesegül Yardimciel, who speaks English, is married and the mother of two daughters.

Yalcin Karatas

Commercial Manager

Electronic Systems Manager (By Att.)

Born in 1974 in Amasya, Yalcin KARATAS completed his undergraduate studies in 1995 in the Department of Electrical and Electronics Engineering, Yildiz Technical University.

Beginning his career initially as an R&D Engineer in the private sector in 1996, Karatas were involved in a number of national and international projects as a specialist and technical manager in various positions at Siemens and Nokia-Siemens between 2000-2008. Serving as the Head of Technical Department and Financial Management Manager at Huawei between 2010-2017, Karatas led several major projects in the fields of business development, technical marketing and sales. He worked as the Sales&Marketing Manager at Andasis between 2018-2019.

Beginning to serve at ISTTELKOM Inc. in March 2020, Karatas continues to work as the Trade Manager.

Holding a number of certificates for sectoral and occupational courses and programs, Karatas has a good command of English. He is married with 1 child.

Zeynep Calman

Human Resources Manager

Zeynep CALMAN completed her undergraduate and graduate studies in Business Administration.

She started her career as a Human Resources Specialist in METRO Cash & Carry in 2002-2006. She worked as the Human Resources Manager of DOGAN Health Group between 2006-2010 as a consultant in health sector employment, and as Project Manager in the establishment, management and organization of the Selection and Placement and Total Quality Management processes during 2010-2012, respectively.

Between 2012-2018, she carried out the functions of Establishing and Developing a Remuneration, Benefits and Human Resources Systems at BERKO pharmaceuticals. She was actively involved in SAP HR, SAP Success Factors Performance and Career Management projects and TURQUALITY Branding Program projects.

In 2018-2019, she worked as the Human Resources Manager at TICIMAX Information Technologies company.

Calman started to work as the Human Resources Project Chief in the Social Services Directorate of IBB ISPER Inc. in 2020 and was subsequently appointed Human Resources Manager of ISTTELKOM Inc. in November 2021 which continues to date.

Taner Citak

Information Technologies Manager

He was born in Istanbul in 1976. Having graduated from Yeşilköy 50. Yıl High School, he received his bachelor’s degree from Yıldız Technical University, Electrical and Electronics Engineering Department in 1997. He got his master’s degree in Business Administration (MBA) from Yeditepe University in 2004.

Between 1997 and 2000, he worked as Project Manager in an international company operating in the industrial automation sector. Between 2000 and 2015, he started working as the department manager at ETC Inc., an active company in the telecommunications sector, and continued to serve therein as General Manager and member of the Board of Directors of the group companies. He performed duty as a senior executive at the IT companies of Çukurova Holding between 2015 and 2017. He functioned, between 2017 and 2019, as the General Manager of Telda Inc., which operates in the sectors of telecommunication and information technologies. As of November 2019, Taner Çıtak has been appointed as the Information Technologies Manager of İSTTELKOM Inc.

Taner Çıtak speaks English and is married with one daughter.

Esin Zeytinoglu

Business Processes and Enterprise Applications Manager

Esin ZEYTİNOĞLU, who was born in Eskişehir, graduated from Süleyman Çakır High School.

She completed her undergraduate education in 1995 in Anadolu University, Faculty of Economics and Administrative Sciences, Department of Business Administration.

Having worked in the field of Finance in various organizations, Zeytinoğlu worked as a Specialist between 1994-1998, Supervisor between 1999-2006, Manager between 2006-2011, Chief Financial Officer (CFO) and Consultant between 2011-2019.

Having served as the Financial Affairs Manager of İSTTELKOM Inc. between 2019-2021, Zeytinoğlu was appointed as the Business Processes and Enterprise Applications Manager in January of 2022, and she still continues to work in this position.


Esin Zeytinoğlu speaks English.

Betul Berran Ortanc

Legal Counsel

Betül Berran ORTANC graduated from the Faculty of Law of Yakın Doğu Üniversitesi [Near East University] in 2014.

Ortanc, who specialized in the fields of Private Law, Law of Commerce, Law of Obligations and judicial proceedings under the roof of well-known Law Offices between the years 2015 and 2017, managed the preparation and the follow-up stages of the contracts in accord with the needs of her local/foreign personal or corporate clients in the field of Law of Contracts.

Ortanc, who worked under the umbrella of Ericsson Telekomünikasyon AŞ (regional business partner of Turkcell İletişim Hizmetleri AŞ) in the year 2017, specialized in the field of Telecommunications Law and worked actively in the management of legal issues regarding the provision of services, all kinds of conflicts (disputes) experienced in the sectors containing technical contents; and, she actively participated in the settlement of conflicts (disputes) and judicial proceedings.

Ortanc, who started working in a Company titled İSTTELKOM Inc. in November 2019, currently manages the legal processes in the fields of Corporate Law and the Law of Commerce. In addition, she follows up on the legal processes regarding the activities within the scope of Electronic Communication Regulations and actively participates in the preparation of Partnership Contracts related to the business activities of the Company and discussions related to the relevant processes. Under the umbrella of our company, Attorney Betul Berran Ortanc also successfully manages the judicial proceedings concerning the disputes between the employees and the employers.

Ortanc has been working as a Legal Counsel in our company since 2019 and speaks English and German.

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