I built an AI app with a tiny team. We scaled it to millions and sold it to MyFitnessPal in under 2 years — here's how.

Jake Castillo cofounded Cal AI in 2024.

Courtesy of Jake Castillo

• Cal AI was acquired by MyFitnessPal less than two years after its launch.
• Cofounder Jake Castillo said their execution speed became the biggest moat against competitors.
• They focused on influencer marketing as their main marketing strategy when scaling the startup.

This as-told-to essay is based on a conversation with Jake Castillo, the 31-year-old CMO and cofounder of Cal AI, based in Los Angeles.