Senior Backend Engineer

Our client is an early-stage fintech startup building a next-generation financial platform that handles real money at scale, internationally. Their backend powers iOS, Android, and Web frontends and integrates with banking service providers, payment rails, and identity/auth platforms.The team is small, highly technical, and moving fast. You'll work directly with the technical founders to set standards and build a highly performant, reliable, and secure system from the ground up. The role has a clear path to Backend Lead or Engineering Lead as the company scales.What You'll DoDesign and build scalable REST APIs powering web and mobile frontends.Integrate with third-party financial services such as payment processors, banking partners, and auth/identity platforms.Own critical backend systems including ledgering, payments orchestration, fraud prevention, and AML compliance flows.Work alongside technical founders to define architecture, coding standards, and engineering culture.Write thorough tests, conduct code reviews, and maintain a high bar for reliability and security.Participate in on-call rotation and incident response for production financial systems.Requirements3-6 years of professional experience building and shipping production backend systems.Strong proficiency in Python; experience with FastAPI or a comparable async framework.Solid working knowledge of PostgreSQL and Redis in production environments.Experience deploying and operating on AWS infrastructure.Strong understanding of REST API design, security best practices, and data integrity requirements for financial systems.Nice to HaveExperience with Rust or Go, particularly for performance-critical services.Prior experience at a fintech startup: banking, credit card, crypto, remittances, or lending.Background working in SOC 2 compliant or otherwise regulated environments.Experience designing for high-availability, multi-region deployments.Tech StackPython (FastAPI), PostgreSQL, Redis, AWS, REST APIs, Rust / Go (open to for performance services)What's on OfferCompetitive compensation commensurate with experience.Meaningful early-stage equity.Hybrid schedule: 3 days/week in the San Francisco, CA office.Comprehensive health, dental, and vision coverage.Home office setup stipend.Direct impact - this is a foundational role at a company building something genuinely hard.