Principal Platform Engineer

About the Role

The Platform organization at Stitch Fix designs, builds, and evolves shared infrastructure and tools to ensure engineering teams deliver software safely, reliably, and efficiently. As a Principal Platform Engineer, you will combine hands-on technical contribution with independent leadership to solve ambiguous problems and eliminate operational friction across engineering. Partnering closely with Engineering Managers, Architects, Technical Program Managers, and cross-functional stakeholders, this role acts as a primary technical multiplier for the organization. By shaping core platform architecture and embedding AI-driven workflows into developer tooling, you directly elevate engineering productivity, system reliability, and overall business velocity.

Responsibilities:

• Own the end-to-end technical delivery of platform initiatives from discovery and design through implementation, rollout, and operational readiness.
• Design and build scalable, observable, and maintainable shared platform capabilities, APIs, gateways, and backend services to streamline developer experience and system performance.
• Evaluate and prototype emerging technologies, including AI agents and automated workflows, turning promising approaches into safe, reusable platform tools.
• Lead technical design reviews and mentor engineers across the organization through code reviews, pairing, and actionable feedback to raise the bar for technical excellence.
• Eliminate manual and operationally expensive work by delivering self-service tooling, automation, and continuous improvement across production systems.

How AI and tools show up in your day-to-day work:

• Leverage modern AI workflows (e.g., GitHub Copilot, ChatGPT, agentic coding tools) to accelerate software delivery, optimize code quality, and automate routine technical tasks.
• Build and operate systems within our core technical landscape, spanning Ruby/Rails, Python, Rust, React/TypeScript, GraphQL, and cloud infrastructure.
• Evolve core platforms so AI agents and automated systems can safely discover capabilities, execute actions, monitor outputs, and recover from failures independently.
• Adapt quickly to emerging platforms, continuously integrating new tools and methodologies into production environments to maximize engineering efficiency.

About You 

• Education: Bachelor’s degree in Computer Science, Software Engineering, or equivalent practical experience.
• Relevant Experience: Demonstrated track record (typically 5+ years) designing, building, and operating complex production systems in platform, infrastructure, backend, or developer tooling environments.
• Technical Expertise: Deep experience with distributed architectures, microservices, APIs, and cloud infrastructure, along with proficiency in languages such as Ruby/Rails, Python, or Rust.
• AI Tooling Capabilities: Hands-on experience using and implementing modern AI-assisted engineering workflows (e.g., AI agents, LLM integrations, Copilot) to optimize developer processes.
• Leadership & Collaboration: Strong problem-solving abilities with proven experience leading complex technical projects end-to-end, communicating tradeoffs clearly, and influencing cross-functional teams without direct authority.
• Physical Requirements: This position may require the ability to sit for extended periods of time, use a computer or other office equipment, and communicate effectively (verbal and written).

Nice to Have:

• Experience working with GraphQL technologies, API gateways, and modern web frameworks like React and TypeScript.
• Exposure to e-commerce, personalization, or large-scale retail engineering ecosystems.
• Proven track record of developing self-service platform tools that safely expose underlying infrastructure to AI agents.
• Active contributions to open-source software, industry whitepapers, or technical communities focused on developer tooling and platform engineering.

Why you'll love working at Stitch Fix...

• We are a group of bright, kind people who are motivated by challenge. We value integrity, innovation and trust. You’ll bring these characteristics to life in everything you do at Stitch Fix.
• We cultivate a community of diverse perspectives— all voices are heard and valued.
• We are an innovative company and leverage our strengths in fashion and tech to disrupt the future of retail. 
• We win as a team, commit to our work, and celebrate grit together because we value strong relationships.
• We boldly create the future while keeping equity and sustainability at the center of all that we do. 
• We are the owners of our work and are energized by solving problems through a growth mindset lens. We think broadly and creatively through every situation to create meaningful impact.
• We offer comprehensive compensation packages and inclusive health and wellness benefits.