Senior Full-Stack Engineer (Senior-Principal Level) A mission-driven startup operating at the intersection of climate and fintech is seeking a Senior Full-Stack Engineer to help build products that make sustainable building upgrades-such as heat pumps, batteries, and EV chargers-more accessible through innovative financing. This is a hybrid role based in New York City, with flexibility on level from Senior to Principal. What You'll Do Own end-to-end feature development, from ideation and archite