Enter your keyword

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.

Taner Citak

Information Technologies Deputy 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.

Starting his career as a Project Manager in an international company operating in the industrial automation sector between 1997 and 2000, Çıtak continued to work as General Manager and Board Member of group companies at ETC AŞ between 2000 and 2015, leading many important telecommunication, GSM, fiber optic infrastructure projects of the company throughout Turkey.

Between 2015-2017, he took active roles in senior management positions at Çukurova Holding, heading the unification of IT infrastructure and smart home projects.

Between 2017-2019, he served as General Manager at Telda AŞ, which operates in the fields of telecommunications and information technologies.

In November 2019, Mr. Çıtak started to work as Information Technologies Director at İSTTELKOM Inc. and was appointed as Assistant General Manager of Information Technologies in January 2023.

Taner Çıtak speaks English and is married with one daughter.

Yalcin Karatas

Sales Marketing and Digital Business Services Deputy General Manager

Infrastructure Systems Manager (Dep.)

Born in 1974 in Amasya, Yalçın Karataş graduated from Yıldız Technical University, Department of Electronics and Communication Engineering in 1995. Karataş continued his education with Bahçeşehir University’s Business for Executives (eMBA) master’s program.

Mr. Karataş started his career as an R&D Engineer in the private sector in 1996 and worked as an expert and technical manager in various positions at Siemens and Nokia-Siemens between 2000 and 2008, taking part in many domestic and international projects.

Between 2010-2017, he worked as Head of Technical Support Department and Financial Management Manager at Huawei and led many important projects in business development, technical marketing and sales.

In 2018-2019, he worked as Sales-Marketing Manager at Andasis.

In March 2020, Mr. Karataş started working at İSTTELKOM Inc., continued his duty as Commercial Manager in 2021 and was appointed as Assistant General Manager of Sales Marketing and Digital Business Services in January 2023.

Karataş, who has certificates in many sectoral professional programs, speaks fluent English.

He is married and has 1 child.

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.

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.

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.

Olcay Karadeniz

Information Technologies Director (Dep.)

Born in 1979 in Cologne, Germany, Olcay KARADENIZ graduated from Abant İzzet Baysal University Industrial Electronics Associate Degree, Anadolu University Faculty of Business Administration, Department of Business Administration and Newport International University Electronics & Communication Engineering.

Between 1996 and 1999, he worked as a design and graphic designer at Turmak AŞ, and between 1999 and 2000 he worked as an IT System Specialist at Maestro Software.

Between 2000 – 2001, he worked as a Supervisor at Motorola, between 2001 – 2004 as a Senior Specialist at Nom AŞ, between 2004 – 2017 as a Transmission Unit Manager at Etc AŞ, between 2017 – 2020 as a Project Manager at Huawei.

Starting to work as Chief of Information Technologies Infrastructure at İSTTELKOM Inc. in 2020, Mr. Karadeniz was appointed as Information Technologies Director (as a deputy) in January 2023.

Olcay Karadeniz is married with one child and speaks English and German.

Sinan Oztimur

IT Service Operations Director

Sinan Öztimur was born in 1974 in Ankara. He had his secondary education in Bornava Anatolian High School, German section in İzmir and high school education in Bursa Science School. Later, he studied Computer Programming at Boğaziçi University and Business Administration at Anadolu University. In 2017, he completed the Executive MBA program of Koç University.

Öztimur has started his professional career in 1997 as a System Engineer in Escortnet. After working in Germany for a short period, he returned to Turkey and started to work as a Network & Security Specialist at İntrakets, a system integrator company.

Afterwards, in 2002, he moved to İŞNET, which is a subsidiary of Türkiye İş Bankası where he worked as a Network and Security Director. Then, he continued his career at PROBİL

In 2007, Mr. Öztimur joined Turkcell Global Bilgi as a Network and Security Specialist. After leaving Global Bilgi in 2016 as an IT Architect, he worked as an expat in Minsk/Belarus for 1 year and worked as a technical Director in many projects as well as Ukrainian operations.

During 2016 and 2019, Öztimur worked as the IT Director of DRD Fleet Leasing. Afterwards, he started at İBB (Istanbul Metropolitan Municipality) subsidiary KİPTAŞ as Information Technologies Director in 2020.

In 2022, Mr. Öztimur started working as SOC Project Manager at İSTTELKOM Inc. and continues to work as IT Service Operations Director.

Sinan ÖZTİMUR is married, has one daughter and speaks English and German.

Şebnem Sozer

Trade Manager

Born in Istanbul, Şebnem Sözer graduated from Private Bilfen High School. She completed her undergraduate education at Yıldız Technical University, Faculty of Mechanical Engineering, Department of Mechanical Engineering in 2002.

She worked in the fields of purchasing and quality management systems. She started her career as an overseas purchasing engineer in the automotive sector in 2002 and worked as R&D engineer in the manufacturing sector, central investment purchasing at Arkas Holding and Sofra Group-Compas, direct-indirect purchasing at Petgaz-Oteko Group and technical purchasing at Milangaz-Oyak Energy. She worked in process improvement-development studies in the companies she worked for.

In November 2022, Mrs. Sözer started to work at İSTTELKOM Inc., where she continues to work as Trade Manager and speaks English.

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.

Follow @isttelkom