AI Engineer

Why join us? Handoff is the AI agent that runs a construction company. We help remodelers automate estimating, streamline operations, and win more work - backed by real-time cost data, intuitive design, and workflows that “speak contractor.” With over 10,000 monthly active users and $6B in annualized project volume already flowing through our platform, we’re becoming the trusted partner for the people who build our homes. We are backed by $25M+ raised from Y Combinator, Initialized, and Greycroft. Our team is distributed across hubs in Austin, São Paulo, and Buenos Aires, and we are deeply focused on building intuitive, high-impact solutions that make a real difference for our users. Backend Software Engineer at Handoff You'll be the dedicated, client-facing engineer behind Handoff's AI-automated takeoff platform for our enterprise construction accounts. Think of yourself as the technical owner of two to three enterprise relationships: you'll embed with each client's software and estimating teams, customize our deliverables to their exact standards, stand up intake and delivery workflows, and iterate until our outputs clear a measurable quality bar. You'll partner with a Construction Account Manager who owns the business relationship while you own everything technical, from first pilot to production integration with their POS/ERP systems. This is a high-ownership role for engineers who like ambiguity, direct customer contact, and being accountable for real business outcomes. What you'll do Own our core AI metrics and the dashboards and alerts behind them. Run experiments on prompts, tools, context and models, from offline evals to controlled rollouts, and decide with data. Build the evals and observability that let the whole team ship AI changes safely. Improve what customers judge us on: accurate outputs, reliable actions and fast answers. Shape the architecture of our agents as the product grows: how context, tools and memory scale. Evaluate new models and providers as they are released, and lead migrations when they are worth it. Work across Handoff’s products and teams, wherever AI quality, speed or cost needs attention. Turn customer-reported AI problems into diagnosed causes and measurable fixes. Share what you learn and raise the bar for AI engineering across the team. About You You’ve owned an LLM-powered feature or agent in production and can point to a metric you moved. You design experiments carefully and can tell a real improvement from noise. 5+ years of software engineering experience, with strong Python and working knowledge of TypeScript/Node, SQL and cloud-based architectures. Practical experience with agents: tool calling, context management, retrieval and structured outputs, ideally with a framework such as LangGraph. Experience building evals and using tracing tools such as LangSmith, Langfuse or similar. You’re comfortable with ambiguity and switching between problems, and you set your own agenda from the data. You care whether the output is right for the customer, not only whether the model call succeeded. Proven experience working in a startup environment is a must. What we offer 💸 Competitive salary in USD 💰 Attractive stock options 🌴 Unlimited PTO 🚛 Relocation allowance 👨‍💻 Top-notch equipment 🧳 Team offsites around the world! If you want to be the engineer customers trust to make AI work in the real world, and watch your work reshape how construction gets done, we'd love to hear from you! Please note that we will only consider applications submitted in English.