Professional sparring partner
Only with experts and professional partners is it possible to understand the specific areas of digitalization and realize how meaningful they can be for companies. 123C offers years of experience in the optimization of digital areas. We work exclusively with partners who are a good fit for us and at the same time are absolute professionals in the fields of digital transformation.
We are 123C Digital Consulting

Harald Grabner
Harald Grabner is founder and owner of the digital consulting agency 123Consulting, which is also partner of 123C Digital Consulting GmbH. After completing his education at WU-Vienna with a Masters of Advanced Studies for Executive Management, he started his professional career as Head of Marketing in international corporations. Coming from an entrepreneurial family, Harald Grabner knows the digital challenges of medium sized companies. His distinctive competence and a high degree of understanding for the “needs” of companies are attributes the characterize his professional work.

Thomas Apollonio
Thomas Apollonio is one of the Managing Directors of 123C Digital Consulting GmbH and Business Partner of 123Consulting. A marketing and digital business expert, he graduated from the University of Advanced Sciences of Journalism & Media Management. Studying integrated Communications abroad at the Hogeschool van Utrecht led Thomas Apollonio on the path of digitalization. With more than 10 years of international consulting and a strong sense for the “digital space”, he likes to support companies in excelling their digital maturity. His knowledge of digital transformation combined with digital maturity sets him apart.

Daniel Gschwandtner
Daniel Gschwandtner is the latest addition to 123C Digital Consulting GmbH and supports the management in marketing and project agendas. Daniel Gschwandtner completed his education in the field of sports and media management and subsequently worked in an event agency for international clients. Within 123C Digital Consulting GmbH Daniel Gschwandtner is responsible for the onboarding of companies and acts as a central contact person in the daily business.

Alex Mitkov
Data Analyst and Project Manager Alex Mitkov is a new member of the 123C Digital Consulting GmbH team. With his statistics degree from the University of Vienna, Alex Mitkov has the necessary expertise for data analyses as well as the use of big data and statistical modelling. Due to his additional education at the JKU Linz in the field of Data Science & Machine Learning, he supports the development of the digital maturity model and is the perfect link in the extended digitalisation toolbox. Alex Mitkov provides a high level of understanding for data and process flows and supports customers in agile project management.

Petra Grossegger
Petra Grossegger will support the 123C Digital Consulting team as a new member with her expertise in various project agendas. In her previous professional career, she has over 15 years of experience in designing and implementation corporate strategies, as well as project management experience in national and international companies. Her customer-oriented approach and empathetic work style are the attributes that distinguish her professional work.
Our Experts

Data Science & Development
Jörg Egretzberger
Jörg Egretzberger is the owner of Trustbit GmbH. His Company offers methodical data development according to the needs of companies. As a strategic data expert, he has more than 15 years of industry experience with top international companies.
Anyone working with customers in the field of technical development today meets the current challenges with a holistic approach. This encompasses the core business and revolves around the central corporate processes in the area of data procurement and subsequent processing. Anyone who thinks in terms of data science must be prepared in advance to be able to create the required data spectrum. Jörg Egretzberger knows the world of data like the back of his hand and moves within the departments in an agile and iterative manner depending on the company’s needs.

Marketing Automation & CRM Expert
Kerstin Wagner
With 15 years of management experience in CRM, Marketing Automation, Digital Strategy implementation and the broad spectrum around Customer Excellence, she brings both technical and process expertise to these topics.
Kerstin Wagner has an international professional education (MBA) and many years of experience in customer excellence and the implementation of digital measures to develop customers along their digital transformation. Her consulting company advises diverse verticals but has as strong focus on the healthcare industry and e-commerce. Her core areas of expertise include data-driven marketing automation and the implementation of comprehensive CRM strategies for companies. Thanks to her excellent conceptual work and the sustainable implementation of digital projects, Kerstin Wagner manages to create a perfect support package for companies of all sizes.

Expert Digital Media & Strategy
Markus Plank
As President of IAB and Managing Director of numerous advertiser companies, Markus Plank not only brings years of industry expertise, he is one of the leading minds in digital marketing strategies in line with data platforms.
Markus Plank provides comprehensive expertise in the field of technical and programmatic campaign conception for the digital marketing mix of medium sized companies. As a leading industry expert, he is a top consultant in the field of strategic media marketing. Furthermore, as the Austrian President of IAB he enjoys dedicating his time to data ownership and the much sought after “cookieless future”. Markus Plank has a broad field of knowledge when it comes to equipping companies with high performance campaign systems and developing them further based on on marketing needs.

Communication Expert
Ronny Hollenstein
As founder an owner of GRUPPE HOLLENSTEIN, Ronny Hollenstein has been dealing with behavior and the hidden resources in people for more than 25 years. As a top professional, he has a comprehensive impact in the field of communication. With his coaching activities he supports in workshops and lectures those people who have to deal with challenging situations.
Ronny Hollenstein has gained years of front row experience and has dedicated himself to the strategic development of communication concepts. In negotiations and media present discussions with top managers, ministers and lobbyists, he was able acquire a comprehensive practical skillset of communication techniques. Ronny Hollenstein has coached many personalities and developed them in their individual needs. Analog as well as digital.

Future Health Visionary
Univ.-Prof. Dr. Siegfried Meryn
Siegfried Meryn is considered one of the most important health experts in the German speaking world and is ranked among the top 10 in Austria´s network of "Future Shapes". He has been chairman of the ORF (=Austrian Broadcasting Corporation). Health Advisory Board for 15 years and, with his expertise, broadcasts weekly TV and radio formats for a broad audience.
Siegfried Meryn is an impressive personality and at the same time a driving force in innovative, medical preventive care. He understands this in a close, technological connection. With a strong international background, he helps those who are needy and socially marginalized. Siegfried Meryn sees the right to a healthy and long life as a basic element for human beings. As a specialist in internal medicine, co-founder of CAPE 10 and the Future Health, Siegfried Meryn offers extensive knowledge in the visionary elaboration of complex ecosystems. He is a top speaker at international congresses and is appreciated worldwide for his vision and expertise.

Strategy Consulting Trade Fairs & Customer Events
Gerald Schneider
Gerry Schneider offers more than 15 years of event & congress management knowledge and industry experience. As Vice President Events at WeAreDevelopers, he ist the expert in the field of digital events, hybrid events as well as in the overall organization of classic, physical events.
Gerry Schneider is a top manager in the event industry and has a large network of international contacts in the MICE scene (Meetings, Incentives, Conventions, Events). As the organizer of one of the largest software developer events in Europe, he is familiar with the most important digital tools and constantly re-evaluates the current needs of the industry. In his role, Gerry Schneider is one of the best expert consultants when it comes to online, hybrid and presence events.

Organisational and Personnel Development
Mag. PhD Alexandra Singer-Weidinger
Mag. PhD Alexandra Singer-Weidinger is Managing Partner at Jobaffairs GmbH, communication scientist and management consultant with a focus on the customized optimization of systematic organizational development processes in the HR sector of profit-oriented companies and organizations within a public mandate.
As a coach, she accompanies people and projects with a vision, analyses and structures workflows and bring dynamism into unproductive processes. Employer branding, candidate journey, onboarding, employee experience are the magic words of modern organisational culture. Mapping authenticity on the web and developing team matches are two of the most important goals to ensure own products and services on a high innovative as well as consistent quality level. Clearly: Success is motivation! Together we demonstrate the possibilities where perspectives can grow. In analogue as we well as digital form. Customised and with guaranteed success.

Marketing Expert
Mag. Georg Wiedenhofer
As long-time CMO of an international retail group, Georg Wiedenhofer is one of the most prominent marketing experts in the country. He uses his expertise in strategy, corporate development and brand management for corporate consulting as well as for building up international marketing units.
As a long-standing president of the Austrian Marketing Club and the Austrian Marketing Confederation, Georg Wiedenhofer has a renowned network of experts and supports 123C Digital Consulting as a manager. For more than 20 years, Georg Wiedenhofer was in charge of the rise and expansion of a well-known retail group. This marketing professional implemented topics such as content marketing, customer relation management, loyalty programs, development of store formats, multi-channel retail, KPI and OKR development for retail brands at an early stage and optimized them on the basis of various factors in value chains. Thanks to this strong background in market research, Georg Wiedenhofer offers complementation management at the highest level.