Senior UI/UX Developer

Optomi, in partnership with a leader in the entertainment and technology industry, is seeking a Senior UI/UX Developer to lead the implementation and continued evolution of user experiences across web-based AI and analytics applications. This is a highly hands-on, design-adjacent engineering role focused on customizing and extending internal platforms such as Open WebUI, LiteLLM Admin UI, Arize, and Archestra. The Senior UI/UX Developer will translate high-fidelity Figma designs into responsive, accessible, and reusable frontend components while ensuring each platform aligns with established brand and design-system standards. The ideal candidate is a strong frontend engineer with deep HTML, CSS, JavaScript, and modern framework experience—not solely a visual or UX designer. This individual should be comfortable working within existing open-source and vendor platforms, integrating with APIs, and simplifying complex, data-heavy AI workflows into intuitive user experiences. What the right candidate will enjoy: Leading frontend implementation for highly visible AI and analytics platforms!Translating sophisticated Figma designs into responsive, production-ready interfaces!Establishing reusable components and consistent UI patterns across multiple applications!Customizing and branding existing open-source, vendor, and administrative platforms!Partnering closely with UX designers, product managers, and backend engineers!Improving the usability of tools supporting prompt experimentation, LLM observability, and agent evaluation!Serving as a technical leader and advocate for frontend quality, design fidelity, and accessibility! What type of experience does the right candidate have? 5+ years of professional experience as a UI Developer, Frontend Engineer, UI/UX Developer, or in a similar hands-on engineering roleDemonstrated experience building UI-heavy, production web applicationsAdvanced proficiency with HTML, CSS, and JavaScriptStrong experience with responsive design, cross-browser compatibility, frontend performance, and modern development practicesHands-on experience translating complex Figma designs, component libraries, and design systems into production-ready interfacesExperience with at least one modern frontend framework, such as React, Angular, Vue, or SvelteExperience with Smelte or a comparable Svelte-based component environmentAbility to build, maintain, and document reusable frontend components and librariesExperience theming, branding, white-labeling, or extending existing tools and administrative interfacesProficiency with Python for UI-adjacent development, templating, lightweight backend integration, or configuration of Python-based administrative toolsExperience integrating frontend applications with REST/JSON APIs and other data servicesStrong understanding of loading, error, empty, validation, and other application states within data-intensive interfacesStrong visual attention to typography, spacing, alignment, motion, iconography, interaction details, and overall design fidelityUnderstanding of usability, information architecture, and UX best practices for data-heavy or AI-focused applicationsExperience working in collaborative Agile environments where design and development progress simultaneouslyAbility to partner with UX designers to clarify design intent, identify edge cases, and resolve implementation constraintsExperience collaborating with backend and platform engineers on frontend integration requirementsStrong written and verbal communication skillsBachelor’s degree in Computer Science, Human-Computer Interaction, Graphic Design, or a related discipline, or equivalent practical experience Responsibilities of the right candidate: Implement and customize user interfaces for Open WebUI, LiteLLM Admin UI, Arize, Archestra, and related AI-driven platformsAlign application interfaces with established visual and interaction standards, including typography, color, spacing, motion, and iconographyTranslate high-fidelity Figma designs into responsive, accessible, and production-ready web interfacesBuild and maintain reusable frontend components, libraries, and shared UI patternsExtend and theme existing platforms through custom CSS, configuration-driven branding, and component-level customizationPartner with UX designers to clarify requirements, identify edge cases, and balance design intent with technical constraintsCollaborate with backend and platform engineers to integrate interfaces with REST APIs and other data servicesImplement effective loading, error, empty, and validation states across data-intensive applicationsEnsure interfaces meet accessibility, responsive-design, performance, and cross-browser standardsConfigure and lightly extend vendor and open-source UI layers while preserving compatibility with future platform upgradesDevelop technical documentation covering component usage, theming conventions, shared patterns, and integration requirementsReview frontend implementations and coach peers on design fidelity, accessibility, and engineering best practicesSimplify complex technical and AI workflows into intuitive, user-friendly experiences Nice-to-have experience: Experience customizing Open WebUI themes or layouts through custom CSS, theming, or Docker-based overridesExperience configuring branding within LiteLLM Admin UI, including logos, color schemes, and root pathsExperience with AI observability or evaluation tools such as Arize, Phoenix, or similar platformsExposure to LLM platforms, prompt experimentation, agent evaluation, or AI-driven administrative workflowsGraphic design or layout experience, including the ability to create brand-aligned icons and visual assetsFamiliarity with design tokens and enterprise-scale design systemsStrong knowledge of WCAG accessibility standardsExperience implementing keyboard navigation, ARIA attributes, and accessible color contrastExperience supporting CI/CD-based frontend releasesPrevious experience providing technical mentorship, design reviews, or frontend code reviews Please note that this is a W2-only opportunity. We’re unable to support C2C arrangements or candidates who require current or future sponsorship.