What stands out about Sam’s approach is his insight on when to build a new framework. While building an AI-powered CRM, his team discovered a critical gap: existing AI frameworks weren’t optimized for TypeScript developers and lacked the quality developer experience they’d come to expect. Rather than compromising, they pivoted entirely to solve this problem for all developers.
For Mastra, the adoption strategy relied heavily on direct feedback loops. During YC, they invited other founders to whiteboarding sessions to deeply understand their AI use cases, rapidly iterating based on this feedback. They found that creating educational content about AI engineering naturally led curious developers to Mastra without aggressive marketing.
On the business side, Sam made the deliberate choice to use the Elastic v2 license instead of MIT–setting boundaries that allow developers to freely use Mastra while preventing cloud providers from simply taking the technology. This balanced approach reflects a maturity many open-source founders eventually reach after their first venture.
Perhaps most interesting is how Sam’s team approached their core differentiator: rather than competing directly with Python-focused frameworks, they doubled down on TypeScript, explicit control flow, and developer ergonomics. This positioning has attracted developers building everything from veterinary AI assistants to aerospace modeling tools using Mastra.
What sustains Sam through the inevitable challenges? “Showing up and logging on to Discord and seeing all the excitement that the folks in the community have,” he told us. “Everyone’s excited about technology again, and we have the tremendous luxury of working on something we care about with folks we enjoy working with.”
For today’s developer tool founders, Sam’s journey highlights a vital lesson: sustainable success comes not from chasing every market trend, but from identifying genuine developer pain points, creating a superior developer experience, and building the right boundaries to ensure long-term sustainability.
Watch the full video on YouTube and leave a comment for a chance to win Sam’s book “Principles of Building AI Agents”
