Senior Full Stack Engineer

Mill; San Bruno (CA); On-site; USD 185,000 - 210,000; Full time

Job summary

Mill is seeking a Senior Full Stack Engineer to join our engineering team as an individual contributor with technical leadership responsibilities. You will drive the technical direction of your project area and mentor engineers, working on full-stack web applications with a focus on end-to-end quality.

Our teams are project-based, and you will rotate across different areas over time. Fluency with AI-assisted development tools (Claude Code, Copilot) is expected as a core part of daily work.

Qualifications

• 5+ years of professional software development with a focus on full-stack development.
• Deep experience with modern frontend frameworks (SvelteKit preferred).
• Strong backend experience with TypeScript/Node.js and serverless AWS Lambda.
• Solid SQL and NoSQL database knowledge.
• Cloud platforms and modern deployment workflows.

Responsibilities

• Lead design and execution of full-stack web applications aligned with business goals.
• Design scalable, secure, and efficient full-stack solutions.
• Own estimates, delivery plans, and surface risks early.
• Develop APIs and user interfaces; ensure maintainability.

Skills

Full-stack development

SvelteKit

React/Vue/Angular

TypeScript

Node.js

API design

AWS Cloud

CI/CD

Problem-solving

Tools

AWS Lambda

Terraform

CDK

Middy

Claude Code

Copilot

Git

Job description

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

1. Lead the technical design and execution of full-stack web applications, ensuring alignment with business objectives and technical standards
2. Design and implement scalable, secure, and efficient full-stack solutions
3. Own estimates and technical delivery plans and surface risks early

Technical Leadership

1. Craft elegant, documented, and sustainable code spanning our full web stack, remaining ready to provide support for our native mobile environment when required
2. Develop and optimize API and user interfaces
3. Use AI-assisted development tools fluently as a standard part of how you write, review, and ship code

Team Collaboration

1. Mentor junior engineers, fostering a culture of continuous learning and improvement.
2. Conduct code reviews and provide constructive feedback to maintain high coding standards.
3. Communicate technical constraints and tradeoffs clearly to your project\'s product manager.

Quality Assurance

1. Champion best practices in testing, CI/CD, and deployment
2. Troubleshoot and resolve technical issues, ensuring minimal downtime and disruption
3. 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 SvelteKit) — we use SvelteKit at Mill but recognize that strong React/Vue/Angular experience is highly transferable, especially with AI-assisted tooling, so prior SvelteKit experience is preferred but not required
• Strong backend experience with TypeScript/Node.js; comfort with serverless architectures (e.g. AWS Lambda)
• Solid understanding of SQL and NoSQL 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: SvelteKit (web, deployed on Vercel), React Native (mobile), AWS Lambda with CDK (TypeScript) and Middy
• Familiarity with DevOps practices and infrastructure as code (e.g. Terraform, CDK)
• Strong understanding of security best practices in web development
• Prior experience working at a hardware company, particularly collaborating with firmware teams — we build physical devices, not just software, and comfort working alongside hardware/firmware engineers is a plus

Key Attributes

• Strong communication and interpersonal skills — especially the ability to partner closely with product without owning the roadmap
• Comfortable holding technical ownership of a project over a sustained period, while staying energized by the opportunity to rotate onto new problems periodically
• Proactive, self-driven, and eager to take ownership of projects
• Passion for mentoring and developing engineering talent

The estimated base salary range for this position is $185k to $210k, which does not include the value of benefits or a potential equity grant. A wide range of factors are considered in making compensation decisions, including but not limited to skill sets, market conditions, experience and training, licensure and certifications, and business and organizational needs.