Sr. Fullstack Software Engineer

Sr. Fullstack EngineerHybrid (NYC)$170k - $190k Base + bonus & equity OverviewA global, high‑growth technology company operating at the intersection of financial technology, consumer platforms, and digital security is expanding its engineering leadership team. The organisation builds large‑scale, consumer‑facing platforms used by hundreds of millions of users worldwide, with a strong focus on quality, long‑term maintainability, and responsible AI‑assisted development.This role sits within a financial products marketplace that partners with major financial institutions to deliver personalised consumer experiences. The position is ideal for a senior‑level engineer who values engineering judgement, thoughtful architecture, and technical leadership over speed alone.ResponsibilitiesOwn and uphold a high engineering quality bar across design reviews, code reviews, testing strategy, and production readinessCollaborate closely with product, design, and engineering partners to shape solutions and evaluate technical trade‑offsArchitect and build frontend‑leaning, full‑stack systems that are modular, composable, and resilient to changeChampion performance, reliability, and maintainability in AI‑assisted development environmentsApply functional programming principles and immutability to reduce side effects and improve system clarityLead the effective use of AI agents for prototyping, refactoring, and exploration while ensuring production‑grade outcomesDrive a robust automated testing strategy across unit, integration, UI/component, and end‑to‑end layersProvide technical leadership through mentorship, delegation, and high‑quality code reviewsMust‑Have QualificationsBachelor's degree in Computer Science, Engineering, or a related field8+ years of experience building production web applications, including senior‑level ownershipPrior experience operating at principal, lead, or staff engineer levelExpert proficiency with TypeScript and React, including server‑side rendered frameworks such as Next.jsStrong understanding of functional programming concepts and immutability in modern frontend systemsAdvanced knowledge of automated testing strategies and CI‑driven feedback loops