James Zammit

James Zammit is a Maltese entrepreneur and the co-founder and CEO of Roark, which tests and monitors voice AI agents, according to Who's Who Malta. "YC has been a dream for both of us," he said when Roark joined Y Combinator's Winter 2025 batch with co-founder Daniel Gauci Mizzi.

Portfolio Tools at AngelList

Zammit is an infrastructure and AI engineer with 10+ years of experience, according to Roark's YC page. As a senior engineer at AngelList, he built core portfolio infrastructure as the company grew from $10B to $124B in assets under management. He also led the development of Relay, an AI-powered portfolio manager processing thousands of financial documents each month.

Earlier, he co-founded a startup showcased at Google I/O 2016 in partnership with Firebase, and received scholarships from Meta and Apple.

Gauci, Roark's CTO, was a senior engineer at Akiflow and spent seven years at Casumo, leading development of a mobile app used by millions of players.

Testing a Dental Clinic Voice Agent

The founders first ran into the problem while building a voice agent for a dental clinic, they wrote in Roark's YC launch. Patients got stuck in loops or failed to confirm insurance. "The only way to test fixes was to call the bot ourselves or read through hundreds of transcripts," they wrote. After hearing the same complaint from other voice AI teams, they built Roark.

Roark lets teams replay real production calls against their newest agent logic before changes go live. Its YC page says Roark processed over 10M minutes of calls in its last six months. The team works remotely across San Francisco, California; London, England; and Malta, according to Roark's about page.