Senior Full Stack Engineer

Mill is a waste prevention technology company reimagining what it means to eliminate waste, starting with food. We build smart systems and infrastructure for homes, businesses, and municipalities that transform food scraps from landfill-bound waste into valuable resources, including chicken feed. Tens of thousands of Mill’s residential food recyclers are already helping households divert millions of pounds of food scraps every year, paving the way for our upcoming launch of Mill Commercial—the industry’s first end-to-end solution for managing, understanding, and preventing food waste in commercial environments (e.g. grocery, restaurants, food services). At Mill, we are passionate about building easy-to-use, beautifully designed technologies that keep food in the food system and out of landfills. Job Summary We are seeking a highly skilled Senior Full Stack Engineer to join our engineering team. This is an individual contributor technical leadership role reporting to the Director of Software Engineering. You will drive the technical direction of your project area and write high-quality code across the stack, while mentoring engineers around you. We've moved away from a frontend/backend split at Mill: every engineer here works full stack, typically leaning toward one side based on strength and interest, and teams are organized around projects rather than layers of the stack. You'll likely anchor on a given project for a sustained stretch — enough to build real depth and avoid constant context-switching — with real opportunities to rotate onto new projects and parts of the codebase over time. AI-assisted development is core to how we build software, not a peripheral tool. We expect fluency with tools like Claude Code as part of your daily workflow, and as a senior level engineer, a role in raising the bar for how the team uses them. Key Responsibilities Technical Leadership Lead the technical design and execution of full-stack web applications, ensuring alignment with business objectives and technical standards Design and implement scalable, secure, and efficient full-stack solutions Own estimates and technical delivery plans and surface risks early Development and Implementation Craft elegant, documented, and sustainable code spanning our full web stack, remaining ready to provide support for our native mobile environment when required Develop and optimize API and user interfaces Use AI-assisted development tools fluently as a standard part of how you write, review, and ship code Team Collaboration Mentor junior engineers, fostering a culture of continuous learning and improvement. Conduct code reviews and provide constructive feedback to maintain high coding standards. Communicate technical constraints and tradeoffs clearly to your project's product manager. Quality Assurance Champion best practices in testing, CI/CD, and deployment Troubleshoot and resolve technical issues, ensuring…