Mike Doernberg on Tweener Talks: The Early Chapters of a Multi-Exit Triangle Founder
How Mike Doernberg went from CPA to serial founder, built multiple companies, navigated early internet chaos, and landed his first major exits.
Who is Mike Doernberg?
Michael Doernberg is one of the Triangle’s most prolific multi-time founders, with a career that spans decades and has generated roughly $500M in combined exits. After moving to North Carolina at 15, he studied accounting at NC State and began his career as a CPA at Ernst & Young. But entrepreneurship was always the gravitational pull.
Mike founded Marathon in the mid-90s as the internet was just beginning to reshape business, spun out SmartPath from an internal project, and later built ReverbNation, Adwerx, and PlayMetrics. Known as an “operator’s operator,” Mike brings a rare blend of strategic thinking, deep operational discipline, and a consistent ability to identify new opportunities inside existing businesses, and turn them into successful spinouts.
We couldn’t share posts like this without our amazing sponsors:
Loving our content? It wouldn’t be possible without our amazing sponsors and our paid subscribers, so THANK YOU!
Featured Gold Sponsor
Featured Silver Sponsor
2025 Sponsors
ExtensisHR - As a Professional Employer Organization (PEO), ExtensisHR empowers tech founders and growing businesses to scale smarter. We take HR administration off your plate—managing payroll, recruiting, employee benefits and retirement plans, compliance, risk, and more—so you can focus on innovation. For over 25 years we’ve leveraged a people-first approach, customer-centric mindset, and deep industry expertise to ensure employers have the tools needed to stay competitive in today’s market.
And special thanks to our friends at Walk West for partnering with us to produce this pod!
How I know Mike:
Mike and I go way back, all the way to the mid-90s, when we were early Triangle founders, building our first companies just a few doors apart on Airport Boulevard. Our offices were neighbors, our founding years overlapped, and our careers kept intersecting as the Triangle tech ecosystem grew.
We became close friends over the years, not just through startup life but through shared interests (including many Star Wars movie premieres together). From the early Stingray and Marathon days to watching each other build company after company, we have been part of each other’s entrepreneurial journeys for almost three decades.
Listen/Watch Our Interview:
In this first episode of a two-part series, we sit down with longtime friend and legendary Triangle founder Mike Doernberg. We go all the way back to Mike’s early days, from being a CPA at Ernst & Young, to consulting during the rise of PCs in the workplace, to building Marathon, and ultimately spinning out SmartPath, a low-code precursor before low-code even had a name.
We discussed:
What the early startup ecosystem looked like before the Triangle was “the Triangle.”
The origins of Marathon and how the rise of PCs and early web consulting created new opportunities.
How a project inside GlaxoSmithKline became the spark that turned into the SmartPath product.
Mike’s philosophy for spinning out products successfully, and why strict separation is essential.
Raising capital in the 90s and early 2000s: angel gauntlets, tough rooms, and memorable TIG stories.
The SmartPath exit to DoubleClick and why Mike now believes they sold too early.
How exiting young led him to a very short-lived “retirement” and why founders struggle to sit still.
How to watch:
Visit Tweener Talks to listen for all audio podcast players
We have a video version on YouTube (make sure to subscribe!)
📌 What’s Next
This first chapter of Mike’s story captures the early sparks: the curiosity, the timing, the hard lessons, and the foundational wins that shaped everything he built next.
Part 2 arrives on December 4th, where we’ll dig into ReverbNation, Adwerx, PlayMetrics, and how Mike thinks about leading, scaling, and reinventing companies today.
Until then, check out more Triangle founder stories at tweenertalks.com!