The Idea
In late 2020, Dr Eric Kwon was running a 900 square foot dental practice in Palo Alto and quietly drowning. His office manager had walked. He was staying up until 2am filling out and posting insurance statements by hand, six days a week on three hours' sleep, and he was nearly $1 million behind on payments owed to his practice. Paper was stacked on his desk, spilling out of filing cabinets, riding home in his backpack.
One of his patients was Steijn Pelle, a Dutch product manager who had done early stints at Coinbase and Robinhood and was hunting for a hard problem. Kwon vented. Pelle did not offer advice or point him at a website.
He asked for a job.
For the next few months Pelle sat on a bar stool near the fridge in Kwon's back office, processing the practice's accounts receivable by hand. At night he rang his technical co-founder Frédéric Renken in Canada, and the two worked out how to automate the thing Pelle had spent all day doing manually. This was the beginning of Lassie.
The Execution
- Mid-2020: Before Kwon, Pelle spent a few weeks filling in at a gastroenterologist's office in Scranton, Pennsylvania. He and Renken then interviewed about 80 doctors and business owners to validate the problem before writing a line of code.
- 2021: Renken, the first product hire at Superhuman, moved to the US and joined full time. Nine months of research had already killed their opening assumption: the back office was not a technology problem, it was a compliance and workflow problem, and no amount of clean UI would fix it.
- 2021 to 2023: Instead of shipping and scaling, the two founders spent two and a half years flying to 100+ practices in Kansas City, Dallas and small-town Kentucky, installing test versions by hand and starting with a single insurance provider.
- Through $1M ARR: Selling was entirely founder-led, and Lassie said no to most of its waitlist on ICP grounds. The first sales hire did not arrive until they had closed hundreds of customers, roughly 100x later than the standard playbook advises.
- 2024: Dr Suffiyah Webb, a paediatric dentist in Newark, met Lassie on a conference floor and volunteered as a test customer. Lassie cleaned up months of unpaid receivables and she has since opened a second location in Hoboken.
- August 2025: With five-figure annual contracts and almost all growth coming from referrals, Pelle said Lassie was on track for $100M ARR within 12 months.
- 3 June 2026: a16z led a $35 million Series A at a roughly $250 million valuation, taking total funding to $47 million. Affirm co-founder Alex Rampell took a board seat.
- Same round: The cap table picked up Rahul Vohra, Zach Perret and Taavet Hinrikus, alongside Gokul Rajaram, Brian Balfour and Night Capital. Advisors include Robinhood's former CFO Jason Warnick and Dr Ed Zuckerberg, a dentist with a reasonably well-known son.
- Today: Lassie runs in 700+ practices across 49 states, removes 250,000 hours of admin a year and handles 98% of payment posting autonomously. Annualised revenue sits above $10 million, well short of last summer's $100M projection, on a market of roughly 160,000 US dental practices.
The lesson?
Pelle could have built this from a laptop in San Francisco. Instead he took an actual job in his dentist's back office, spent months posting claims by hand, then spent two more years flying to Kentucky to install software one practice at a time. Rampell compares him to a Method actor. It fits: nobody out-researched Lassie because nobody else was willing to be that bored for that long. Pelle's own diagnosis of why most founders lose is three words long. Founders are too impatient.