Principal Software Engineer, Frontend - Design Systems

HubSpot is evolving its design systems and is seeking a Principal Software Engineer to lead the frontend technical direction for the Trellis design system. This role involves driving the evolution of the design system, collaborating with product teams, and mentoring engineers to ensure high-quality user experiences.

Responsibilities:

• Drive the evolution of the Trellis design system during HubSpot's 2026 UI modernization, shaping the entire product experience
• Work closely with Trellis team and Product teams to build and expose a world class component library where the default experience sets a high visual bar, beautiful, fast, consistent, and intentional
• Define the accessibility capability model for Trellis: the controls, toggles, and patterns that let customers and users meet their needs, rather than designing to the lowest common denominator by default
• Define and develop internal tooling to support the evolution of Trellis at scale, giving the team the ability to test and iterate on theme and style changes
• Define and develop the migration tooling that moves HubSpot's Canvas applications to Trellis at scale, codemods, automated refactoring pipelines, and coding agent workflows that make the right path the easy path for product engineers
• Make practical decisions about the component library API interface and abstractions exposed to engineers and designers
• Leverage coding agents to ship production code regularly and lead complex initiatives from idea to rollout
• Mentor Staff and Senior engineers, and drive organizational thought leadership on frontend craft. Setting the bar for how HubSpot builds UI, not just on the Trellis team but across the engineering organization
• Partner with engineering leads, PMs, and UX to align frontend direction with HubSpot's product roadmap

Requirements:

• 14+ years of software engineering experience, with a track record of Principal-scope impact on your organization's most critical business and customer needs
• Deep expertise in React, TypeScript, and modern JavaScript frameworks, architecture, and infrastructure. Experience with modern component libraries and tooling, we're using BaseUI, and StyleX, and our theme deployment infrastructure leverages Cloudflare Workers
• Experience developing and shipping a production design system that is used at scale
• A hands-on builder mindset. You lead by writing, debugging, reviewing, shipping, and thrive on feedback
• Fluency with AI coding agents, and a perspective on how they change frontend development at scale, and a belief that they will