Senior Full Stack Engineer / Startup experience / React / Node

Philadelphia, PAOpen to RemoteFull Time$150k - $185kSenior Full Stack Engineer I'm working with an innovative fintech company that's hiring a Senior Full Stack Engineer to join their Core Engineering team. This team builds the foundational systems that power authentication, data privacy, AI enablement, and internal tooling across the organization. Hybrid (1–2 days/week) if you're local to an office in Silver Spring, MD, New York City, San Francisco, Miami, or DenverRemote candidates are welcome if you are not local to an office Responsibilities Build and maintain core services supporting authentication, data privacy, AI infrastructure, and internal tooling Own projects from technical design through implementation, deployment, and ongoing support Develop scalable backend services using Node.js, TypeScript, and relational databases Build modern frontend applications with React (or similar frameworks) Partner with Product, Data, and Operations teams to deliver reliable, scalable systems Improve system reliability, observability, and performance across critical workflows Design and enhance APIs, shared libraries, and platform tooling used across engineering Participate in architecture discussions, code reviews, and technical documentation Requirements 7+ years of professional full stack software engineering experience Strong experience with Node.js, TypeScript, React (or similar), and Postgres (or another relational database) Experience building scalable, production-grade web applications and backend services Comfortable owning projects end-to-end with minimal direction Strong understanding of observability, reliability, and production debugging Experience collaborating across cross-functional engineering teams Experience using AI-assisted development tools such as Cursor, Claude Code, GitHub Copilot, or similar Experience with GraphQL is a plus Nice to Have Authentication & Identity (OAuth, SSO, Auth0, session management) Data Privacy & Trust Systems AI Enablement / LLM infrastructure Internal developer tooling and platform engineering experience Additional Information No sponsorship or visa transfers are available for this position.