Our Team

The TestingTime Unicorns – all around the world


Reto Lämmler: CEO & co-founder TestingTime
Reto Lämmler
Co-Founder and CEO

Test early and often is Reto’s mantra for good Interaction Design. Reto started TestingTime at the beginning of 2013. As the CEO, Reto leads the vision and mission of the startup. Prior to TestingTime, Reto worked as an Interaction Designer and Usability Consultant with his own 58rocks GmbH. At doodle.com, he gained international startup experience as VP Product Management. He holds an MAS in Interaction Design and a BSc in Computer Science.

Oliver Ganz
Co-Founder and CTO

Oli is a classic full stack ninja. Since 2015 he gets up every morning to make TestingTime a step better. As TestingTime’s new CTO, he is responsible for the development and operations of the platform. If there is some time left, he spends it on a football field, playing the accordion or with dice in his hand playing DnD. He worked as a Software Engineer for doodle.com, where he fell in love with growth and helped the company grow from 5 up to 30 million unique visitors.

Dave Lieber
Dave Lieber
Chief Customer Officer

Customers and people are Dave’s heartbeat and he wants to create customers for life! His mission is to delight our customers with high quality services and turn them into loyal and great product evangelists. In Dave’s backpack we find, besides some smelly Swiss cheese, more than 20 years of experience in Services and Customer Success. His backpack is further packed with a survival kit consisting of his lovely wife, two little crazy girls and a bottle full of dreams in which he runs a boutique hotel in the middle of the Centro Storico in Florence, renovates houses, building furniture and writes a children’s book. Find out what Dave has to tell you, by watching this video interview.

Customer Success

Corinne Schröttenthaler Customer Success Manager
Corinne Schröttenthaler
Customer Operations Lead

Corinne is our Customer Operations Lead. After a long detour in the world of retail, where she ended up as a backstock manager, she began working in visual communication while studying. These experiences helped her to develop a proficiency for easy-to-understand, engaging communication approaches and general customer satisfaction. Corinne loves drawing in her free time and is constantly expanding her collection of antique jewelry.

Éléonore Doucet
Customer Operations Specialist

Before I joined TestingTime, I acted as an exports consultant for French companies exporting goods and services from France to Switzerland. Now, I support the customer success team, especially with our French-speaking clients and tests users. Outside of work, I do a lot of sports and love to travel. Cats are my favorite animals.

Céline Kaiser
Customer Operations Specialist

Before joining TestingTime, Céline gained experience in various areas of the hospitality industry. During her studies in International Management, she worked in a customer care centre on the phone and answered all kinds of questions. In the Customer Success Team she can now bring all this experience to bear and ensure that customers, as well as test users, have a great experience with TestingTime. With her open mind and healthy curiosity, she loves to find new solutions for challenges. On Céline’s desk you will always find a good cup of tea and at least one plant that she is currently mothering. Get to know her a bit better in this short video interview.

Felix Fay
Customer Operations Specialist

Felix has gained many years of sales and marketing experience in the international tourism and hotel industry before joining TestingTime. His organisational and customer oriented skills contribute to the efficiency of our operations team. Among his side projects, he’s studying to become a wedding planner. He loves to host dinner parties and offer a cozy environment. Making customers feel special comes naturally to him.

Kerstin Dreesen
Kerstin Dreesen
Customer Operations Specialist

After many years in local, sports and automotive journalism, Kerstin has worked as a freelancer for more than 100 customers in the fields of text and online marketing since 2007 before she joined TestingTime at the end of 2018. Her experience in dealing with customer wishes and needs is the perfect basis for working in the Customer Success Team. In her leisure time, Kerstin plays golf or trains for the next half marathon. Her dog Lotte doesn’t leave her side.

Human Resources and Finance

HR Manager Gökhan Güldür TestingTime
Gökhan Güldür
Senior HR Manager

With the rapid growth of TestingTime, Gökhan joined us after completing his studies in October 2018 as our new HR Manager. As a passionate karate coach, he also acts as a sparring partner, contact person and motivator in his spare time. He is responsible for recruiting employees with the right (TestingTime) DNA for our company and his target is to ensure the strategically and operationally best possible HR service to reach our goal of becoming # 1 in Test User Recruitment in Europe.

Oliver Müller Finance Controlling TestingTime
Oliver Müller
Finance & Controlling

Oliver has been responsible for Finance and Controlling at TestingTime AG since December 2018. He is happy when his Excel-sheets support management’s decision-making process by providing meaningful and forward-looking financial data. As guardian of the financial resources, he furthermore tries to promote budget-compliance with his colleagues. Oliver used to work as Head Reporting for an Investment Fund and got his accounting know-how from working with a Swiss non-profit foundation. He completed his degree MAS Corporate Finance CFO at FHNW.


André Riner Senior Key Account Manager
André Riner
Key Account Manager Switzerland

Just like a teenager, André is eager to learn new things and meet new people. And it is to these traits that he owes his stellar career in market research, marketing consulting, and key account management. At TestingTime, André joins Dino in caring for our Swiss clientele. In his spare time, he enjoys spending time with his family and staying active: you will see him jogging, cycling, or coaching high school track and field teams. He’s also known to cheer his daughters on at handball tournaments.

Matthias Kase Team Germany TestingTime
Matthias Kase
Key Account Manager Germany

Matthias has been working in the area of services for digital products for 4 years now. He is very familiar with the everyday challenges in agile work environments. Having joined the team at the beginning of 2019, Matthias, who lives in the Berlin metro area, is responsible for our German customers. All in all, he has 9 years of experience in various sales positions. Most recently, he worked at a startup in Berlin. If you’re looking for an easy way to recruit test users, get in touch with Matthias.

Ahmet Sakali
Key Account Manager Germany

Easy to handle, ready to deliver. This applies to TestingTime and to me as well. Before I came to TestingTime, I was already here and helped to make TestingTime known throughout Europe. After a stopover in Data Driven Marketing, I am back in the team and look forward to picking up where we left off – establishing TestingTime as Europe’s #1 in Test User Recruitment. Outside of work, I enjoy being with friends or travelling, preferably in the sun and by the sea.

Guillaume Dozier
Guillaume Dozier
Key Account Manager France

Before Guillaume joined TestingTime, he worked for French startups looking to develop their business in Canada. Now, he’s helping TestingTime’s clients in France find the right test users for their research. Outside of work, he fights climate change by planting trees with the non-profit organisation he founded. Also, he is a dog person.

Marc O'Brien
Marc O'Brien
Key Account Manager UK

Marc calls London home, where studied for a degree in Criminology. He spent a decade as an account manager for a varied customer base at a market-leading recruitment company. Today, Marc looks after the UK market for TestingTime. Always thinking outside the box and considering solutions that benefit his clients, he enjoys collaborating with a broad spectrum of companies and personalities. Outside of work, he is busy trying to score goals for his local football team.

Matthias Holtz Team Germany TestingTime
Matthias Holtz
Customer Success Manager Germany

Based in Cologne, Matthias takes care of our customers in western Germany. Until recently, he made a living as an author and documentary filmmaker. When he joined the glamorous world of SaaS a couple of years ago, he was a little surprised at how much he liked it. “Consulting is more like filmmaking than you might imagine: you listen to people and try to get an idea of their situation and their challenges. And then you develop a solution that will please them.”

Pascal Ammann
Pascal Ammann
Inside Sales Manager

As a trained draughtsman specialised in building construction, user experience was already close to Pascal’s heart when designing a building. Then he gained his first experience in Sales & Marketing at a language travel agency while at the same time studying tourism. One of the key points was to identify customer needs and through that create the ideal experience. Now he is happy to use his know-how at TestingTime’s Sale team while still learning something new every day. In his spare time, he enjoys gravel biking and cheering for his favourite football team.


Ines Misura
Head of Marketing

Before joining TestingTime, I had the opportunity to develop as a marketer within different industries and in companies of different sizes. I have always put the expectations, needs and wishes of the customer at the centre of my work. I am happy to apply my previous expertise at TestingTime and also to acquire new knowledge. For me, standing still is not an option and, as is well known, the world belongs to the brave.

Maggy Mächler
Inbound Marketing Manager

Maggy is a very dedicated Marketing Manager with over ten years of experience in Sales & Marketing. Her skills include analytical thinking and creative problem-solving. She goes the extra mile to give customers the best possible experience.

Nora Schenker
Senior Marketing Manager

I am responsible for the Test User Pool at TestingTime. I make sure the pool contains the right test users to successfully meet our customers’ needs. This way, I am able to combine my interests in UX, data science and marketing perfectly. I completed my Master’s degree in media and communication science at the University of Zurich where I also worked as a research assistant. Before joining TestingTime, I was the Marketing Lead at a Swiss startup in the beverage industry. In my spare time I love to go on spontaneous trips, film my adventures and turn them into short videos.


Ion-Alexandru Ursachi
Lead Software Architect

With a passion for software craftsmanship and constantly looking to expand his knowledge, Alex moved to Zurich in search for new challenges. Joining TestingTime’s engineering team was an easy decision as it was a fit for his skills and personality. Apart from coding, he enjoys spending time with his family or listening to music. Alex graduated with a Bachelor in Computer Science and worked as a Software Engineer for about 8 years before joining TestingTime.

Wei Liu
Software Engineer

Wei joined TestingTime as a front-end developer in mid-2019. She is experienced in web application development and is passionate about advanced technologies. In her spare time, she likes traveling and photography. Before joining TestingTime, Wei lived in the United States for about 5 years. During that time, she got her Master’s degree in Electrical Engineering and worked as a full-stack developer building a SaaS platform.

Eneko Olivares
Software Engineer

After five years working as a Software Engineer in the ICT research field, Eneko moved to Switzerland to expand his experience and search for new challenges. He joined TestingTime’s engineering team at the end of 2020. He is passionate about core backend technologies and DevOps. In his spare time, he enjoys spending time with his dog, gaming, watching sitcoms and going to the gym.

Miloš Manojlović
Miloš Manojlović
Senior Frontend Developer

After multiple years of work in the field of computer graphics, Miloš continued his passion for all things visual with a pivot towards front-end development. Eager to hone his skills even more in that area, he joined TestingTime at the very beginning of 2021. When he’s not refining and polishing application front-end, he’s hiking, gaming or tinkering with old PC hardware.

Nico Kupfer
Nicolas Kupfer
Senior Angular Frontend Developer

After studying mathematics and working all sorts of jobs in all sorts of places (hiking guide, construction, teacher, bee farmer, hotel receptionist…) Nico has finally settled in the wonderful world of JavaScript – a very creative job in a wonderful team. As a Mensa member, he has a passion for learning and challenging himself; will start new private projects for which he has no idea and figure out the steps along the way. All his possessions fit in a mini cooper and is currently building his own camper van. He loves sleeping in his tent in places where others won’t.


Product Manager Cosima Lefranc TestingTime
Cosima Lefranc
Head of Product

Creating a great technological product from beginning to the end is Cosima’s job at TestingTime. With a dual background in Business Intelligence and Quantitative Finance, Cosima is on a constant quest to find new data-driven insights from our product usage. She enjoys talking to our users and discovering new ways in which we can help them become more successful. In her free time, she loves to try every possible apps you could imagine, speaks 3 languages fluently and she has travelled to more than 50 countries. Cosima graduated with a Bachelor in Economics and a Master in Quantitative Finance from the University of St. Gallen.

Ivana Stoyanovska Gjorgjiev
Ivana Stoyanovska Gjorgjiev
Product Manager

Delivering user-centred products which create value to users is at the heart of Ivana’s job at TestingTime. She is very passionate about discovering user needs through different product discovery techniques. Ivana enjoys focusing on the user and working with engineers to bring new product ideas to life. Before joining TestingTime, she was part of successful technology companies in Skopje, London and Zurich. Outside of work, Ivana enjoys every moment with her family and her two-year-old daughter. They love to spend quality time in nature, play with LEGOs and roleplaying.

Janine UX Designer TestingTime
Janine Totz
UX Architect

Create wonderful user experiences – that’s Janine job at TestingTime. She has formerly worked as a Head of Design at an advertising agency and developed a lot of user interfaces, graphics and screen designs. That’s why she completely understands how to challenge products and services and how to optimize them both content-related and in appearance. Ever since she has lived in Lucerne she is totally hooked by their famous carnival. Plus, her passion for playing the drums have inspired her to join and actively participate in one of the music groups. Janine has studied print and media technology in Berlin and is a certificated BEng.

Beatriz Gómez Pérez
Digital Product Designer

Before I joined TestingTime, I have done quite diverse jobs. I worked as UX/UI Designer for SaaS B2B cybersecurity start-up dedicated exclusively to the creation of software for SOCs (Security Operations Center). After that I joined DDB, an important international communication company, as UX/UI Designer for SEAT in Barcelona. Outside of work, I love to go to pottery classes and leave the screen for a while to improve my creativity with my hands.

Council of wisdom

We are very proud to have well known people from the scene on board with us. As startup founders you do most things the first time. To get advice from people who tackled similar challenges in the past is very helpful to us.

Twan Vollebregt
Board Member

Twan joined TestingTime’s board in 2018 as part of the second financing round. As a successful serial entrepreneur and senior executive, he has already taken two startups from idea to exit and is currently working on his third. This full-cycle experience has taught him the importance of vision and strategy, and Twan will take any opportunity to discuss product & commercial strategy in particular.

Cristian Grossmann
Board Member

Cris is the CEO and Co-Founder of Beekeeper, an award-winning digital workplace app that digitizes the non-desk workforce in 137+ countries by connecting operational systems and communication channels within one intuitive platform. Prior to founding Beekeeper, Cris worked for Accenture on high profile international projects in the field of IT Strategy for the financial and public sectors. Cris studied Chemical Engineering and got his Ph.D. in Electrical Engineering, both at ETH Zurich. Before moving to beautiful Zurich, Cris was born and raised in an entrepreneurial Swiss-Mexican family in Mexico City.

Picture of Eric Reiss - Advisor at TestingTime
Eric Reiss
Advisory Board Member

Our business advisor Eric’s first usability testing took place when he was three years old – he talked his mother into modifying a rocking horse so it didn’t rub his knees. Ever since, he has never accepted things as they are, but has always worked to make things better. Today, he is an internationally recognized expert in usability and user-experience design. His best-selling book, Usable Usability, is now available in four major languages – English, German, Chinese, and Japanese.


If you want to have a significant impact on our success story, apply now!