About Us

IST constitutes one of the most respected and credible Independent Software Vendors in the Greek market, being in the forefront of the Greek software industry since 1991.

Think Big, Act Small


International Software Techniques S.A. (doing business as IST) is a privately held company of Greek interests, established in 1991.

IST currently functions both as an Independent Software Vendor (ISV) and as a Value-Added Reseller (VAR) for third-party software products and services.

The company is headquartered in Marousi, Athens, Greece. The management team owns 100% of the share capital, allowing the company to pursue a coherent growth strategy.

IST dedicates itself to delivering sophisticated services and solutions for specific, high growth and demanding industries, such as telecommunications, banking & finance, and pharma.

We primarily address the needs of large-sized and Enterprise-level organizations (either private, publicly traded, or multinational), while we also offer our services to major international software vendors, I.T. solution providers, I.T. integrators and digital agencies (acting as their designated outsourcing partners).

At IST, we are a strong advocate of the "Think Big, Act Small" management approach: think big, authentic ideas about solving customers’ problems, making better products, providing valuable services, exploring innovative solutions, and creating value. But, at the same time never stop acting like a start-up; staying humble, treating every employee like the owner, and having everyone on the frontline.

We make a conscious and continuous effort to combine the strengths of a big organization with the hunger of a start-up. We build excellent relationships with our clients, suppliers, employees, and other stakeholders; we groom future leaders at all levels, and we balance their short-term goals with their long-term visions.

Key Facts


  • Country of incorporation: Greece

  • Year of establishment: 1991 (as Ltd. / Limited Liability Company)

  • Legal form change: 2005 (transformed into Societe Anonyme)

  • Current structure of entity: S.A. – equivalent to Corp. (USA) / plc (UK) / AG (Germany)

  • Type of entity: Privately held - shareholders management team owns 100% of share capital

  • Certified Public Accountants / Auditors: SOL Crowe (member of Crowe Global)

  • Doing Business As (DBA): IST

  • Legal name (English): IST - International Software Techniques S.A.

  • Legal name (Greek / Latinized form): IST - Διεθνείς Τεχνικές Εφαρμογών Α.Ε. / IST - Diethneis Technikes Efarmogwn A.E.

  • VAT number / TIN: EL095526161

  • Local tax authority: FAE Athinon

  • GEMI (General Electronic Commercial Registry) number: 006264401000

  • D-U-N-S number: 499928021

  • NACE (Rev. 2): SECTION J / DIVISION 62 / GROUP 62.0 / CLASS 62.01 (Computer Programming Activities) / CPA CATEGORY 62.01.1 / CPA SUBCATEGORY 62.01.11

  • ISIC (Rev. 4): 6201 (Computer Programming Activities)

  • SIC code (US): 7371 (Computer Programming Services)

  • NAICS code (US: 1997 / 2002 / 2007 / 2012 / 2017): 541511 (Custom Computer Programming Services)

  • EORI number: GR095526161

  • Certifications: ISO 9001:2015 / ISO 14001:2015 / ISO 22301:2012

  • Company registered office & HQ: Flias 1, 151 24 Marousi, Athens, Greece

  • Respective time zone:

    • WINTER TIME: Eastern European Time (EET) - UTC/GMT +2 hours

    • DAYLIGHT SAVING TIME: Eastern European Summer Time (EEST) - UTC/GMT +3 hours

  • Standard work week: Monday to Friday (excluding national holidays)

Management Team
  • Mr. Antonios Roussos

Company Founder & Consultant to the Management


  • Mr. Georgios Roussos

President of the BoD / General Manager


  • Mr. Thanos Prinjos

Chief Executive Officer


  • Mr. Panayiotis Tzagkarakis

Chief Technology Officer


  • Mr. Antonios Apostolakis

Chief Knowledge Officer


  • Mr. Konstantinos Madias

Chief Operating Officer

Portfolio of Services


We offer our client base a diverse portfolio of sophisticated services and solutions, tailored to their specific needs.

Our software services are addressed to end clients (such as large-sized and Enterprise-level organizations), while we also act as preferred outsourcing partners (for local and international software vendors, I.T. solution providers, I.T. integrators and digital agencies).

Current portfolio of services:

  • Bespoke Software Development (for high growth industries, such as telecommunications, banking & finance, pharma)

  • Proprietary Software Solutions (for Communications Service Providers / "Telcos")

  • Managed Services

  • Time & Material Services

  • Staff Augmentation / Staffing Services

  • Value-Added Reselling / Value Added Services (for third-party software solutions)