Senior Backend Engineer (US)

We are looking for a Senior Backend Engineer with 5+ years of experience to own and build the core backend infrastructure powering a modern B2B payments platform. You'll be someone with high agency who thrives in ambiguity, turning messy, real-world problems into reliable production systems. This role sits at the heart of the product, working on core data infrastructure, payments systems, and internal tooling that directly impacts business outcomes. If you've built backend systems in payments and want to operate with true end-to-end ownership at a fast-moving startup, this is the role for you.

What you will be doing

• Building and owning production backend systems for Slope's core data and payments infrastructure using TypeScript/Node.js

• Designing APIs, services, data models, and contracts that other teams depend on, with a focus on correctness and reliability

• Creating internal tools that help teams review data, understand decisions, and move faster without sacrificing quality

• Owning ambiguous projects end-to-end, defining the problem, proposing a path, shipping production slices, and iterating

• Improving the reliability, latency, and correctness of systems that directly affect payment decisions and customer experience