Backend / Systems Engineer - Agent Infrastructure

xHeron takes responsibility for guest operations for short-term rental businesses: guest communication, coordinating teams, resolving issues. Today, that operating scope is delivered through a mix of people, software, and AI. We're building the technology to handle more of that work autonomously, without turning into another tool customers have to supervise. We're looking for a Backend / Systems Engineer to build the software that makes this reliable: persistent state, safe execution, permissions, and recovery across humans, agents, and external systems. Tasks What You'll Own Data models & state: Build backend services and data models that track operational work, ownership, and outcomes over time. Asynchronous workflows: Develop asynchronous workflows with reliable handling of retries, timeouts, external events, and interrupted execution. APIs & tool execution: Build shared APIs and tool-execution interfaces, including authorization and customer-data isolation. Knowledge infrastructure: Improve the infrastructure for storing, versioning, and serving operational knowledge. Platform quality: Strengthen testing and observability while evolving the existing platform alongside our CTO, AI engineer, and product engineering team. Requirements What Makes You a Great Fit Strong backend engineering skills in Python and/or TypeScript/Node.js, with willingness to work across both. Practical experience with PostgreSQL or another relational database, including data modeling and transactions. Experience shipping and maintaining production backend services. Familiarity with background jobs, queues, or event-driven processing, and an understanding of failure handling and data consistency. The ability to investigate production problems, design clear interfaces, and deliver maintainable solutions. Around 3+ years of backend engineering experience is a useful guide, not a hard requirement. The systems you've owned matter more than the number. Nice to have: experience with workflow engines, multi-tenant applications, authorization, FastAPI, or agent tooling. Prior LLM experience is not required. Strong backend fundamentals and an interest in learning the agent domain matter more. You May Not Be a Great Fit If You want to configure infrastructure, not design the systems underneath it. You need a fully scoped spec instead of investigating ambiguous problems yourself. You've never shipped and maintained a production backend service. You favor clever or complex solutions over simple, maintainable ones. You're looking for a defined 9-to-5. Benefits Why Join xHeron Real ownership: you're working on foundational product architecture, not cloud configuration, with substantial technical ownership from day one. Direct founder access: you'll work directly with our CTO, shaping how humans and agents work together. We invest in our own: your ownership grows as the system does, this isn't a role with a ceiling. Upside: VSOP alongside salary; you're building this with us. Our Process Intro call (30 min): a conversation with Friedrich (CTO) about your background, what you've built, and why this role. Technical take-home case study: a short, real engineering problem, close to what you'd actually be building. Case study interview (1 hour): you walk us through your thinking, not just the final code. Culture fit (30 min): meet both Founders and make sure it's a fit both ways.