Felix Huettenbach, the German-born founder now based in Dubai, founded the fitness-technology company W8X in 2017, at a time when he was also studying at MIT and moving between investment, health technology and teaching roles. Those early years laid the groundwork for the moment Huettenbach became co-founder and CEO of Sameday Health during the COVID-19 pandemic in 2020, and for his current work as a co-founder of the data center developer Terranum.
Huettenbach's first post-university role placed him on the investment team at Aurelius Equity Opportunities in Munich between 2016 and 2017. His work there covered market entry analysis and financial models, the type of analytical groundwork that sits behind investment decisions. For someone who would later become an angel investor himself, the role offered an early view of how capital evaluates a business.
In 2017 he founded W8X, a company working in fitness technology. The available record on W8X is brief, and details such as its product, customers or later development are not part of the established facts about him. What the founding does show is timing: he started W8X in the same year he began his MIT program, choosing to build a company while studying entrepreneurship rather than after.
Fitness technology sits at the intersection of hardware, software and consumer behaviour. That combination fits the profile of a founder trained in both mechanical engineering and business administration at TUM, and it also points toward the health-adjacent fields that would define his next steps.
Huettenbach's role as Chief of Staff at Quantgene brought him into a company using machine learning to detect cancers early from standard blood samples. A Chief of Staff typically works across functions on behalf of leadership, and in his case the job became a bridge to the pandemic. When COVID-19 began, he set up a unit at Quantgene that offered COVID-19 testing to companies.
Then came his next company. Because the general public also needed fast COVID testing, Huettenbach co-founded Sameday Health in September 2020 with one site in Venice, Los Angeles, which first operated as Sameday Testing. It offered PCR and rapid tests at walk-in locations with online booking and digital results, and under his leadership as CEO it had grown to 55 locations across the United States by April 2022.
According to the company, priority PCR results arrived in under 24 hours and rapid antigen results in about 15 minutes, with the booking system linked to local laboratories. The company said that system was custom-built by four MIT software engineers, a link to the institution where Huettenbach himself had studied entrepreneurship. In March 2021, with Huettenbach as CEO, Sameday Health added an at-home Concierge Service, in which licensed medical professionals tested clients at home, and reported hundreds of thousands of COVID-19 tests performed since fall 2020. Huettenbach said at the time: "we are committed to providing accessible care." The line echoes the mission he describes on his own website, making healthcare more affordable, transparent and approachable.
From 2018 to 2020, Huettenbach served as a Guest Lecturer and Global Entrepreneur in Residence at the University of Massachusetts Boston. The appointment began a year after he founded W8X and overlapped with his MIT program, so he was teaching entrepreneurship while practising it. For students, an entrepreneur in residence offers access to someone who is currently running ventures rather than describing them from a distance.
Read as a sequence, his early career shows a steady movement from analysis to operation. At Aurelius he modelled businesses; at W8X he founded one; at Quantgene he helped run one in a technically complex field; at UMass Boston he explained the process to others. Each step added a different perspective that would be useful when building Sameday Health under the pressure of a pandemic.
The same thread continues today. Huettenbach, a founder, investor, adventurer and YouTuber based in Dubai, is a co-founder and partner of Terranum, which develops renewable-powered data center campuses, and he invests in founder-led companies. According to his own disclosures, his angel holdings include SpaceX, xAI, the YC company Platus and House of Macadamias. His short summary of his operating philosophy, "Execution beats narrative.", reads like a description of the years in which he founded W8X: less talk about a future company, more time spent building one. His reflections on building and backing companies are shared on LinkedIn.