Frontend Engineer, UI Platform

Description

The company behind this role is a financial infrastructure platform for businesses. Millions of companies, from large enterprises to early-stage startups, use it to take payments and grow revenue.

The UI Platform team, called Sail, builds the base layer for the Dashboard and many other user interfaces. The team owns the company's design system, which helps engineers build consistent, accessible, fast, high-quality interfaces at scale.

The team builds and maintains reusable components, design tokens, theming, documentation, and developer tooling used by engineers and designers across the company. Two major projects are underway. The first is Sail for Agents: generation infrastructure, documentation, agent integrations, and automated quality checks that help AI coding agents build high-quality interfaces safely at scale. The second is updating the visual language of the Dashboard, one of the company's largest UI surfaces, while modernizing its codebase.

Responsibilities

• You will help build and improve the design system and the tools that let engineers and AI coding agents produce strong user interfaces.
• You will own frontend projects from defining the problem through to rollout, working mostly on your own with designers, product engineers, and other Sail engineers.
• Your work spans reusable components, themes, and docs, plus agentic tooling, automated quality checks, and modernizing the Dashboard's foundations.
• Scope and carry projects through design, build, testing, and rollout.
• Build and maintain accessible, fast, well-tested components, themes, and frontend APIs used across the company.
• Create tooling, docs, and automated checks so engineers and AI agents can use Sail well and meet the company's UI quality bar.
• Work with product designers and engineers to find their needs and turn repeated UI patterns into design-system features.
• Help move the Dashboard's visual language forward and migrate legacy UI patterns as its codebase is modernized.
• Raise the bar on accessibility, internationalization, observability, performance, reliability, and developer experience in the design system.
• Review code, join technical discussions, and write docs that improve the team's output.

Requirements

• Minimum requirements: you must meet these to be considered. If you do, you are encouraged to apply. Preferred qualifications are a bonus, not a requirement.
• Daily fluency with AI-assisted and agentic development tools, including reviewing, checking, and improving the code they generate.
• At least 2 years of professional frontend experience, or equivalent practical experience, building, shipping, and debugging web apps.
• Solid knowledge of modern frontend technologies and frameworks, including browser fundamentals, responsive design, and accessibility.
• Can scope and deliver open-ended frontend projects alone, making sound technical and product tradeoffs with little oversight.
• Strong at problem-solving and debugging, with care for testing, maintainability, and the end-user experience.
• Strong written and verbal communication, and able to work well with designers, product engineers, and other partners.
• Preferred qualifications (a bonus, not required):
• Experience on a design system, frontend platform, or shared component library.
• Experience with developer tooling such as build tools, package managers, codemods, lint rules, or large monorepos.
• Experience building tools, integrations, or automated evaluation and quality systems for AI coding agents.
• Experience using docs, developer feedback, or adoption data to improve a developer-facing product.