Backend Engineer, AI
Builds and scales backend systems, APIs, and data pipelines for AI-powered features, agents, and automation in a fintech payments platform using stablecoins. Requires 3-8+ years experience with Node.js and production LLM systems.
About the job
What You'll Do
- Be a critical part of the technical and product roadmap
- Build and scale the backend systems, APIs, and data pipelines that power Rain
- Design and ship AI-powered features, agents, and automation into our core platform
- Build shared AI infrastructure: composable tool interfaces, eval frameworks, and permission-aware data access
- Rapidly ship new capabilities to our customers and internal teams
- Work embedded with the business, understand the workflows you're building for firsthand
What We're Looking For
- Experience with Node.js and other backend technologies
- 1–3+ years building production systems that use LLMs, tool calling, structured outputs, prompt architecture, retrieval patterns
- A builder mentality, someone who experiments with side projects
- Comfortable with ambiguity, you can take a loosely defined problem, make decisions, and ship
- This position is for folks with 3–8+ years of experience, compensation will be based on experience
Nice to Have
- Eval framework design, building systematic ways to measure AI quality
- Fintech experience (neobank or card issuing experience gets extra brownie points)
- Experience building internal tools or platform systems at a growth-stage company
Skills
Node.js, LLMs, Tool Calling, Structured Outputs, Prompt Architecture, Retrieval Patterns, APIs, Data Pipelines, Eval Frameworks, Fintech
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