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. Senior Fullstack Engineer at Handoff You’ll play a pivotal role in shaping both the frontend and backend architecture of Handoff, ensuring seamless performance, scalability, and a best-in-class user experience across mobile and web. This role goes beyond coding - you’ll be deeply involved in understanding contractor workflows, using AI-powered automation to simplify processes, and driving the technical evolution of our platform. You’ll collaborate closely with design, product, and AI teams to build a high-impact, user-centric system. WHAT YOU'LL DO * Develop scalable frontend and backend systems, including APIs, services, and interfaces, to support AI-driven workflows, with a focus on usability, speed, and performance. * Develop and maintain scalable backend APIs that power AI-driven workflows. * Partner closely with product, design, engineering, and AI teams to align on requirements and ensure that our solutions deliver seamless, cohesive user experiences. * Provide constructive code reviews, share knowledge, and mentor fellow engineers, contributing to a collaborative, high-performing team. * Evaluate and adopt new tools, frameworks, and processes to improve frontend performance, efficiency, and code reliability, always with the customer experience in mind. ABOUT YOU * Bachelor's degree (or similar) in Computer Science, Engineering, or a related field. * 7+ years in frontend and backend development, with a proven track record of building scalable, high-performance applications. * Strong proficiency in Typescript, Node and React Native. * Experience working with Python, SQL, and cloud-based architectures. * Experience optimizing API performance and database queries, reducing latency and ensuring seamless data flow between backend and frontend. * Experience designing and implementing responsive, high-quality frontend components that ensure a seamless, intuitive user experience across both mobile and web platforms. * You write clean, maintainable, and testable code while enforcing best practices in software development. * Experienced in working with design and product teams to deliver cohesive solutions, with clear and proactive communication. * Comfortable in a fast-paced environment, you’re quick to adapt to changing priorities and balance rapid iteration with high-quality outputs. * Proven experience working in a startup environment is a must. * Proficiency in English, both written and verbal WHAT WE OFFER * 💸 Competitive salary in USD * 💰 Attractive stock options * 🌴 Unlimited PTO * 🚛 Relocation allowance * 👨‍💻 Top-notch equipment * 🧳 Team offsites around the world! If you’re passionate about building exceptional user experiences across the stack and want to join a team that values product impact and technical excellence, we’d love to hear from you! Please note that we will only consider applications submitted in English.