Senior Front-End Developer

Senior Front-End Developer (leaning Full Stack)

What You Will Do
• Own the Front-End Experience
• Own the front end end-to-end: the Chainlit-based chat application and the React/TypeScript components and interaction patterns layered on top of it
• Own the rendering pipeline for rich AI output: streaming responses, markdown, code blocks, tables, citations, diagrams (Mermaid), maps (GeoJSON), and generated images, so that complex output is legible and trustworthy
• Design and build interaction patterns for agentic workflows: tool-call progress, multi-step reasoning states, human-in-the-loop confirmations, and graceful handling of long-running or partial responses
• Apply industry best practices and emerging front-end patterns specific to agentic AI: streaming UX, agent and tool-call visibility, and interfaces for user-built and multi-agent workflows
• Own client-side state, streaming, and real-time updates (WebSocket/SSE), so the interface stays responsive while the backend is still working
• Build file upload, document preview, and results-display experiences for knowledge search and research workflows

Work Across the Stack
• Work close to the application layer in Python where Chainlit lives; customize rendering, session handling, and interaction behavior beyond what the framework gives you out of the box
• Partner with backend engineers on the API contract the front end consumes; shape it so it serves the user experience, and implement the glue when the boundary is fuzzy
• Implement front-end-facing integrations with our data sources and APIs, including LLM provider outputs, knowledge search, and tool results
• Write production-quality code across the stack: readable, tested, reviewed, and documented

Partner with Research and Design
• Work hand-in-hand with our human-centered researcher and designer to turn user insights and design intent into interfaces that actually serve the user, not just approximations of the mockup
• Translate research findings and usability feedback into concrete UI changes; close the loop by shipping, measuring, and iterating
• Treat design fidelity, interaction detail, and edge-case behavior as part of the job; sweat the small things because they are what users feel
Own Quality, Performance & Accessibility
• Own front-end performance from the user's perspective: time-to-first-token, perceived latency, and smooth streaming under real network conditions
• Ensure accessibility (Section 508 / WCAG) is built in, not bolted on; we serves a federal user base and accessibility is a requirement, not a nice-to-have
• Build front-end observability: client-side error tracking, usage analytics, and the instrumentation needed to know what users actually do

Collaborate and Drive Craft
• Rapidly prototype and iterate on new capabilities; ship, measure, and improve
• Establish and improve front-end coding standards, design review, and testing practices
• Communicate technical decisions clearly to both engineers and non-engineers; no one should have to guess what you built or why
• Mentor and unblock other engineers with a bias toward ownership and speed
• Ensure strong privacy, security, and compliance in all UI, data handling, and integrations

Basic Qualifications
• Bachelor's or Master's in Computer Science, a related field, or equivalent practical experience
• 7+ years of professional software engineering experience building and operating production web applications, with a primary focus on the front end
• Experience designing and building for AI, LLM, chat, or agentic products: streaming responses, citation and source display, tool-call visibility, and building for uncertain or probabilistic output
• Working knowledge of industry best practices and front-end patterns specific to agentic AI (streaming UX, agent and tool-call visibility, human-in-the-loop, multi-agent workflows)
• Strong proficiency in TypeScript/JavaScript and deep, hands-on expertise with React and its modern ecosystem (hooks, state management, component architecture)
• Working proficiency in at least one backend language (Python strongly preferred, given Chainlit) and comfort operating across the client/server boundary
• Proven experience shipping complex, interactive UIs in high-velocity environments where you owned features end-to-end
• Strong CSS and responsive design fundamentals
• Experience with real-time UI patterns: streaming responses, WebSockets or SSE, and optimistic/partial rendering
• Solid understanding of web performance, cross-browser behavior, and front-end testing
• Strong attention to detail and a high bar for code quality; you care about how it looks, how it feels, and how it reads six months later
• Clear, direct communicator who gives and receives feedback well and makes the people around them better
• Self-starter with a high bar and a high sense of urgency; you do not wait to be told what to do next

Preferred Qualifications
• Hands-on experience with Chainlit or similar conversational/LLM front-end frameworks, including customizing rendering and interaction behavior
• Experience with rich client-side rendering: markdown, syntax highlighting, Mermaid diagrams, data visualization, or map rendering
• Experience working directly with UX researchers and designers in a tight build-measure-learn loop
• Experience on Microsoft Azure and within CI/CD pipelines; comfort deploying and operating what you build
• Familiarity with design systems and component libraries at scale
• Track record in startup or early-stage environments: comfort with ambiguity, rapid iteration, and wearing multiple hats
• Experience in big tech or scaled tech organizations building customer-facing products