Senior Full Stack Engineer Job San Bruno area,California USA,Software Development

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.

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 minimal downtime and disruption

Monitor and optimize application performance

Required Qualifications

5+ years of professional experience in software development with a focus on full-stack development
Deep experience with modern frontend frameworks (e.g. React, Vue, Angular, or Svelte Kit) — we use Svelte Kit at Mill but recognize that strong React/Vue/Angular experience is highly transferable, especially with AI-assisted tooling, so prior Svelte Kit experience is preferred but not required
Strong backend experience with Type Script/Node.js; comfort with serverless architectures (e.g. AWS Lambda)
Solid understanding of SQL and No

SQL database systems
Experience with cloud platforms (we run AWS) and modern deployment workflows
Fluency with AI-assisted development workflows (e.g. Claude Code, Copilot) as a genuine part of your day-to-day practice — not occasional or exploratory use
Strong software architecture fundamentals (e.g. microservices, serverless)
Excellent problem-solving and debugging skills

Preferred Qualifications

Experience with our specific stack:
Svelte Kit (web, deployed on Vercel), React Native (mobile), AWS Lambda with CDK (Type Script) and Middy
Familiarity with Dev Ops practices and infrastructure as code (e.g.…