Erin Weigel

Erin Weigel delivers impactful, user-centric products and tells stories about how she does it.
Her career started in customer service when she worked retail and waited tables. This experience developed her service mindset, which guides her unique design approach.
She has A/B tested thousands of design changes at, the world’s largest online travel website, where she worked as Principal Designer for 9 years. Her specialties are conversion design and building experimentation cultures. She’s currently writing Design for Impact: Improve Customer Experience and Drive Business Growth with Conversion Design, published by Rosenfeld Media, which will be released in 2024.

Learn more about Erin and all the stuff she does at
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Maurice Beerthuyzen

Maurice Beerthuyzen has been active in the CRO world for years. As a program manager and researcher, he saw and experimented with hundreds of sites. In addition, Maurice is very skilled in setting up a solid CRO organization within companies. Once again Maurice will take you into the beautiful world of website optimization with his limitless enthusiasm.

Martijn Versteeg

Martijn Versteeg, with an experienced background in online and email marketing, works as a driven Customer Journey Consultant at Yellowgrape. Over the years, he has developed a keen insight into optimizing customer journeys, with data and neuromarketing playing a central role in every contact moment. In his current role at Yellowgrape, he brings a pragmatic approach to the customer journey, carefully analyzing and fine-tuning the customer experience.

Jan Marks

Jan is passionate about driving innovation and growth specializing in digital transformation, CX/UX optimization. As a change manager, he thrives on helping companies flourish in the digital realm, navigating rapid shifts in competitive landscapes and expanding into new markets.

Leonie Eckhardt

Leonie Eckhardt has been in the center of Yellowgrape’s CRO and Customer Journey team for over two years now. Besides her role in experimentation and qualitative research methods, her expertise lies in making the strategic connections between teams. Translating business targets to practical experiments.

Lukas Vermeer

Lukas Vermeer is an experienced experimentation practitioner. His specialty is designing and building the infrastructure and processes required to start and scale A/B testing to drive business growth.

Lukas combines industry experience in online experimentation and data science with an academic background in computing science and machine learning. For eight years, he was responsible for A/B testing at, widely acknowledged leader in online experimentation. Lukas grew the in-house experimentation team from four to thirty people, and became the first Director of Experimentation in the company.

Lukas plays an essential role in making A/B testing an integrated part of business processes. He is an advocate for accessibility of experimentation, helping people from any background (product owners, designers, developers, writers) to make the right decisions. He has accepted two Experimentation Culture Awards; once on behalf of and once on behalf of the Vista Experimentation Hub. His impact was recognised in the Harvard Business Review story “Building a Culture of Experimentation” (March – April 2020 issue).

Lukas co-authored multiple influential academic papers on the topic of online experimentation. He spoke at 30+ conferences, including Growth Marketing Summit, CXL Live, and Google Catalyst Conference, SIGIR and KDD.

Currently Lukas is employed as Director of Experimentation at Vistaprint. He is also available as a freelance speaker and consultant to help businesses grow their experimentation culture.