Principal Platform Engineer

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.

• 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.