Calvin App

Nick Sonnenberg spent eight years on Wall Street as a high-frequency algorithmic trader, operating at microsecond speeds and processing billions of dollars in daily trades. He was making seven figures by age 25-26, but despite the financial success, something was missing. A pivotal moment came when he saw a friend working on his laptop by a pool—it crystallized that the real win wasn't the paycheck, but autonomy and interesting work. "For me, work being counseling interesting is the most important thing and having the freedom to work on what you want whenever you want," he explained.

Nick connected with Ari Meisel (co-founder of his outsourcing company Les Deux) and realized the automation principles he'd built for finance could transform personal productivity. He self-funded Calvin App with $200,000 of his own capital and raised another $200,000 from friends and family. The core insight was simple but powerful: there's nowhere to store "someday" plans (restaurants, events, experiences), and scheduling these plans requires an average of 7.2 back-and-forth communications between two people. Calvin solved both problems by letting users store someday events and then proposing meeting times using an overlapped calendar view—similar to Outlook's free/busy feature, but for personal friends, without exposing full calendar details.

Nick got strategic early exposure by building on top of Twitter's infrastructure. He integrated Twitter Friend Finder to detect which contacts also had Calvin installed. This innovative use of the API caught Twitter's attention, and Calvin was featured at Twitter's developer conference. That single feature launch drove the app into the App Store and generated approximately 400 downloads within a few weeks—a solid start for a brand-new productivity app with no paid marketing.

As of the interview, Calvin was in public beta and preparing to launch fully. Nick was looking to raise approximately $750K in a convertible note, targeting a $6-8M pre-money valuation to minimize dilution while retaining growth upside. He had two monetization strategies in mind: affiliate partnerships with platforms like OpenTable and Fandango, and deeper brand integrations where companies like SoulCycle could leverage Calvin's calendar overlap data to send hyper-targeted promotions. Nick acknowledged he was catching up on the softer skills—marketing, design, web development—that he'd neglected during his math and engineering-focused career, but his Wall Street discipline and product instincts gave Calvin a strong foundation.