[Applicants: Be among the first 25 applicants | Industry: Software Development and IT Services and IT Consulting | Type: Full-time | Level: Mid-Senior level] Agreement type: This is an on-site full-time employment role, with direct hiring by the client.On-site role based in Palo Alto, CaliforniaRelocation/visa support.Our company descriptionMission is a platform for hiring, vetting, and managing software development talent.It enables our clients to connect with the world’s best talent to build mission-critical software products.About the clientOur client is a cutting-edge technology company focused on developing the next generation of enterprise intelligence systems.Their teams are building AI-driven infrastructure that powers advanced automation and decision-making at scale.The work involves designing and deploying highly reliable distributed systems, as well as leveraging large language models and agent-based workflows to create production-ready solutions.They foster a culture of deep technical excellence, ownership, and fast-paced execution.Engineers are encouraged to apply strong fundamentals while using modern tooling and AI-assisted development to deliver complex systems with precision and reliability.This is an onsite, high-commitment environment ideal for engineers eager to tackle technically demanding challenges with significant real-world impact and growth potential.About the roleOur client is looking for a Senior Frontend Software Engineer to own and evolve the user interfaces for AI-driven developer and audit tooling.This role focuses on building high-performance, real-time web applications that surface agent behavior, streaming model outputs, system evaluations, and human review workflows.You will operate at the boundary between advanced backend AI systems and end users, translating complex, dynamic behavior into interfaces that are fast, clear, and intuitive.This is a hands-on senior IC role with meaningful ownership over frontend architecture and user experience.What You’ll DoDesign and build complex frontend applications using TypeScript and ReactOwn frontend architecture decisions, including routing, state management, caching, and rendering strategiesImplement real-time UI patterns for AI systems, including:Streaming model outputs /Agent actions and tool execution traces /Live system feedback and updatesBuild and maintain reusable component systems and design tokensEnforce accessibility, responsiveness, and cross-browser reliabilityDevelop rich interfaces for data review, annotation, and human-in-the-loop audit workflowsBuild advanced editors, tables, and visualizations for technical usersInstrument analytics, monitoring, and experiments to measure UX quality and performanceSet and maintain performance budgets; identify and resolve regressionsPartner closely with product, design, and backend teams to turn research and prototypes into production-ready experiencesWhat You Bring5–8+ years of professional frontend engineering experienceStrong, production-level expertise with TypeScript and React (Next.js, Vite, or similar)Experience building and operating large, complex frontend applicationsRecent hands-on experience with AI-enabled or agent-based systems, ideally in B2B environmentsComfort integrating with streaming or asynchronous backends and real-time data flowsDeep understanding of frontend performance, reliability, and maintainability, including:Performance profiling and optimization / Bundle sizing, code splitting, and rendering strategies /Hydration, virtualization, and client/server rendering tradeoffs.Proven experience shipping real-time user interfaces connected to AI or streaming systemsStrong testing discipline, including automated testing (e.g., Playwright, Jest)Ability to remain hands-on while contributing to technical direction and mentoring othersStrong collaboration skills across design, product, and backend teamsExperience working across both startup environments and larger engineering organizationsPreferred ExperienceOwnership of frontend architecture or design systems at a SaaS or developer-focused companyFamiliarity with modern API and data transport patterns (e.g., GraphQL, typed RPCs)Experience with advanced browser capabilities (e.g., web workers, WASM)Exposure to collaborative or state-synchronization systemsData visualization experience for technical or analytical usersStrong fundamentals in frontend security and accessibilityExperience with monitoring, observability, and experimentation toolingWork Environment & ExpectationsOn-site role based in Palo Alto, CaliforniaHigh-intensity, execution-focused engineering cultureStrong emphasis on ownership, accountability, and production reliabilityOpportunity to work on foundational AI systems with significant technical depthCompetitive compensation, healthcare coverage, equity participation, and relocation / visa support