There's a moment in every startup's life when the obvious question reveals itself as the hard one. For Kurt Ruppel and his co-founder Kyle Mack, that moment came inside Checkr's offices in San Francisco. Checkr runs background checks on people. Efficient, modern, API-first. But the question that nagged them wasn't about people - it was about the 30 million businesses those people worked for. Who was checking on them?
Nobody had built a clean answer. Banks had stacks of paperwork. Fintechs had manual workflows stitched together with spreadsheets and hope. Businesses applying for credit cards, bank accounts, or payment rails were being put through processes that hadn't meaningfully changed in decades. Ruppel and Mack decided to fix it.
In 2018, they co-founded Middesk. They applied to Y Combinator on October 1st. The acceptance call came November 2nd. By the time their Winter 2019 cohort hit Demo Day, they had already landed a term sheet from Accel. Sequoia wasn't far behind. A $4M seed round closed before the pitch was even finished.
The ability to verify a business quickly, accurately, and at scale is no longer optional - it's mission-critical.
- Kurt Ruppel, Fast Company World's Most Innovative Companies 2025
Ruppel's path to infrastructure-builder ran through a surprising detour: cognitive science at UC Berkeley. Not computer science. Not economics. The study of how minds process, perceive, and make decisions. It's an unusual foundation for someone who now builds the systems that determine whether a business can get a bank account - but watch how he talks about data signals and you start to see the connection. Understanding what information humans need to form trust, and building the infrastructure to deliver that information cleanly, is exactly what Middesk does.
After Berkeley, he moved into engineering - first as a senior software engineer at Zendesk, the customer service platform that gave an early generation of SaaS engineers a masterclass in building at scale. Then came Checkr, where he ran engineering teams and met the man who would become his co-founder. Checkr taught them both the same lesson: good infrastructure makes hard problems disappear.
Middesk took that lesson and aimed it at business identity. The platform connects to hundreds of government agencies, Secretary of State databases, IRS records, and private data sources to answer one question: who is this business, really? Is it legitimate? Is it compliant? Is it the kind of entity a regulated institution should be doing business with?
As CTO, Ruppel runs the technical architecture behind that question. He publishes detailed quarterly product updates, leads webinars on the hardest verification edge cases (sole proprietors, which lack the structured filings of incorporated businesses, are a particular obsession), and builds the API-first infrastructure that lets Middesk customers onboard businesses in seconds rather than weeks.
The recognition has arrived in waves. Forbes Fintech 50 in 2024. Fast Company's World's Most Innovative Companies in 2025. Banking Tech Startup of the Year in 2025. Best Data Product for Lenders by Tearsheet. Two of the three largest U.S. banks now use the platform. Over 600 customers. 150,000 businesses verified every week.
None of it looks like an accident when you understand what Ruppel was actually building: not just a compliance tool, but primitive infrastructure - the layer of trust that every subsequent financial transaction runs on top of.
