Inside César Casella’s Full-Stack Twitter Funnel for 6–7 Figure Agencies

In this episode of Founders Future, with host Zach Young, we sit down with César Casella, an 18-year-old growth partner helping 6- and 7-figure agencies turn X (Twitter) into a predictable client acquisition engine. César shares his raw journey from growing up in financial hardship in Portugal to experimenting with countless online business models before finally finding traction. After years of making zero income, losing accounts, and facing intense self-doubt, he broke through by building a full-stack Twitter acquisition system that blends positioning, content, inbound and outbound DMs, and scalable infrastructure.César breaks down how his agency helps founders dominate their niche on X through deep positioning work, high-volume strategic content, DM funnels, appointment setting, and backend systems that convert attention into booked calls and revenue. He also shares hard-earned lessons on pricing models, why free and rev-share-only offers fail, how referrals fueled rapid growth, and why commoditized agencies are disappearing in an AI-driven market. This episode is an unfiltered look at resilience, obsession-level execution, and what it really takes to build leverage and authority early in the agency space.