Sema4.ai · 8 hours ago
Senior Frontend Engineer
Atlanta, GA
Full-time
Onsite
Senior LevelSema4.ai is seeking a Senior Frontend Engineer to design and build modern web applications with a strong focus on user experience. The role involves leading UI feature development, driving UX quality, and contributing to light backend work while mentoring other engineers and improving team processes.
Artificial Intelligence (AI)Generative AISoftwareWeb Development
Responsibilities
Lead UI feature development end-to-end: define approach, design component structure, implement flows (navigation, forms, data-heavy screens), and ship polished interactions
Drive UX quality: propose UX improvements, spot inconsistencies, raise the bar on micro-interactions, and ensure a cohesive experience across the product
Build reusable components and patterns that scale (design system contributions, shared utilities, consistent UX)
Integrate with APIs (REST + RPC/typed APIs such as tRPC): loading states, error handling, caching, retries, pagination, and optimistic updates where appropriate
Own client-side state strategy (local vs server state, derived state, performance considerations)
Ensure quality and reliability with automated tests, code review, and strong typing
Own UI performance and accessibility: responsive design, a11y best practices, rendering performance, and maintainable styling
Implement or extend API routes/procedures and input validation
Work with authentication/session concepts and authorization-aware UX
Debug issues spanning frontend ↔ backend ↔ network
Mentor engineers, set patterns, and improve team velocity through thoughtful reviews and documentation
Identify and execute refactors that improve maintainability without disrupting delivery
Partner with design/PM/engineering to clarify requirements and deliver iteratively
Qualification
Required
Strong experience building production web UIs with a modern component-based framework (e.g., React)
Excellent UX judgment: you can spot issues in flows and visual hierarchy, and you sweat the details (usability, consistency, accessibility)
Strong TypeScript/JavaScript fundamentals (types, async, functional patterns, maintainable code)
Solid API integration skills: request/response modeling, error handling, caching strategies, and secure client behavior
Comfort with frontend architecture: routing, shared component libraries, state patterns, and incremental refactors
Testing mindset: ability to write and maintain unit/integration tests and prevent regressions
Pragmatic full-stack ability: comfortable reading and making small changes in backend code to support frontend features
Advanced knowledge of AI tooling: Cursor, Claude Code, Codex
Preferred
Experience building or maintaining a design system or reusable UI component library
Familiarity with auth flows (SSO/OIDC, token/session handling) and role/permission-based experiences
Experience with real-time features (websockets/streaming) and event-driven UI
Basic database familiarity and understanding of how APIs interact with persistence layers
Strong product sense: ability to translate ambiguous requirements into clear UX and iterative delivery
Company
Sema4.ai
Sema4.ai is an AI platform that empowers organizations to build, deploy, and manage agents designed to transform knowledge work.
Founded in 2024
51-200 employees
Funding
Current Stage
Growth StageTotal Funding
$55.5M2025-06-04Series A· $25M
2024-01-29Series A· $30.5M
Leadership Team
Paul Codding
Co-Founder, SVP of Product and Customer Experience
Ramachandran Venkatesh
CTO, Co-founder
Recent News
2025-09-12
Company data provided by crunchbase