• You'll work directly with founder and CEO Sebastian Delgado (co-founder of Fei Labs), taking ownership of meaningful chunks of backend, full-stack, and security work. • Design and build backend services connecting custody, fiat rails, policies, and operational workflows. • Implement and maintain APIs and services for ACH, wires, cards, permissions, AML/compliance workflows, and reporting. • Implement and review Solidity smart contracts, focusing on correctness, safety, and upgradeability. • Contribute to threat modeling, security reviews, and audit/vendor management. • Collaborate on the design and implementation of customer-facing applications (currently Dart/Flutter). • Translate user and operational needs into product and UX decisions, especially around permissions, approvals, and money flows. • Own parts of audit/security review processes for your areas of the stack. • Coordinate with external security firms. • Build internal systems and processes with a security-first mindset appropriate for handling customer funds.