Regional Coordinators

IxDA's Regional Coordinators sustain and coordinate the growth of local groups internationally. Regional Coordinators are nominated from the IxDA community and volunteer their time.


Tonia Bartz (United States)

North America


Tonia M. Bartz is an observer and user advocate by day and by night; studying how people use various items or services and how the user experience can be improved at all levels. She holds a Masters in Information Architecture and Knowledge Management from Kent State University. By day, she is Senior Human Sciences Designer at General Dynamics C4 Systems. At night, her focus switches to the local and UX communities.

Tonia is an active member of the Interaction Design Association (IxDA), where she is the North American Local Group Regional Coordinator and a member of the Phoenix local group as well as within various community activities including Smunch, a local monthly brunch meetup in the Phoenix area and a local choir, Voices Lifted that sings at hospices around the valley. In the past, she was president of a non-profit and is currently the Director of Community Outreach for Sailbear Labs, a 501c3 nonprofit focused on teaching students aged 12-18 filmmaking and storytelling. Additionally, she loves volunteering and participating in community events.



Rikki Teeters (United States)

North America


Rikki is passionate about creating a better future for humanity — one experience at a time. She has devoted her life to making both digital and physical interactions more human.

After studying Interaction Design at Miami University, Rikki pursued her love of design and technology by entering the field of UX. To further her understanding of user's mind, Rikki became a Certified Usability Analyst in 2013. She has conducted user research, usability testing, and user centered design practices, to create engaging experiences for Fortune 500 companies, complex international brands, and on the verge start-ups.

Rikki stays active in the international UX community by speaking at industry conferences and maintaining her role as Regional Coordinator for IxDA North America. She is now an Experience Architect at Rockfish Interactive.



Santiago Bustelo (Argentina)

Latin America


Santiago has worked as a designer and programmer since 1983. He had his first contact with interaction design in 1997 – designing business simulations. He holds a degree in graphic design from the University of Buenos Aires, where he has also taught.

Santiago has participated in design and development projects for Argentina, Chile, Spain, the United States and England since 1997. He is the coordinator of the Buenos Aires IxDA local group.


Wayne Coughlan (South Africa)

Africa and the Middle East

Wayne Coughlan is from Cape Town, South Africa and is a co-local leader for IxDA Cape Town. He teaches in the Graphic Design Program of the Faculty of Informatics & Design at Cape Peninsula University of Technology.


Birgit Geiberger (Germany)



Birgit is a Creative Director UX, Visual & Interaction Designer holding an MA in Graphic Design. She has 16 years of professional experience in the United States and Europe, working for clients such as Olympus, the EDEKA Group, Monster, The Seattle Times and Toyota.

In addition to being the founder and local leader of the IxDA Hamburg chapter, she shows her enthusiastic engagement for the community through further activities such as supporting the inaugural Interaction Awards as the Co-Chair Outreach Europe 2012. We are thrilled to have Birgit continue her support of the IxDA community as the Regional Coordinator for Europe.


Sudhindra Venkateshamurthy (India)

Asia Pacific


Sudhindra is a Certified Usability Analyst, with over 12 years in various roles and capacities architecting User Interfaces. He heads Experience Design for Sapient Nitro in India. He has extensive hands on experience in the length and breadth of the User Centered Design Methodology, having led several medium to large projects across Corporate Banking, Airline, News and Media, Drug Discovery, Healthcare and IT Domains.

Sudhindra has conducted User Experience training and is also a regular speaker at local conferences and events. He has authored many articles and stories that have appeared in the recently published book “UX Story Tellers” as well as local newspapers. He heads the Asia region of the Interaction Design Association (IxDA) and is a prominent activist in the Bangalore UX scene, having been one of the core organizers of World Usability Day events in the past years.