Sajeev Magesh is Co-Founder of ReasonBlocks (YC P26), a Y Combinator-backed AI infrastructure startup building the runtime layer that makes AI agents smarter, cheaper, and more reliable at scale.

Sajeev studied Computer Science at Stanford and is a USAMO qualifier with published research in Nature Sustainable Agriculture and Nature Scientific Reports, applying machine learning to real-world problems.

Sajeev has been building alongside co-founder Rohan Vij for over 11 years, and his work has earned recognition from the United Nations, Google, and Microsoft, reflecting a rare blend of academic rigor and entrepreneurial drive.

Prior to ReasonBlocks, Sajeev founded Social Fulcrum, a volunteer-nonprofit matching platform connecting over 35,000 volunteers with 4,200+ organizations, raising $41,000 in corporate grants from companies including Microsoft, Adobe, and Canva.

ReasonBlocks addresses a critical gap in AI agent infrastructure by catching failures mid-run and building a private reasoning library that compounds across every deployment, enabling agents that get cheaper and more reliable the more they run.