Top Senior Front End Developer Jobs in Los Angeles, CA

Lead frontend architecture and implementation for new products using React, TypeScript, and Next.js. Collaborate with Product and Design, define patterns and testing strategies, ensure performance, accessibility, and observability, mentor engineers, and drive cross-team initiatives to align frontend systems with backend APIs and platform requirements.

Design, build, and support React/TypeScript applications; set accessibility and design-system standards; make technology decisions balancing security and quality; enhance performance, stability, and security; collaborate across product, design, ML, and infrastructure; mentor engineers and reduce technical debt; work across the stack including APIs and integrations.

The Frontend Engineer will build user-facing interfaces for AI software development, utilizing technologies like TypeScript and React, while ensuring code quality and user experience.

Lead front-end architecture and build high-performance React/TypeScript web applications, integrating with back-end APIs, ensuring type safety, testing, CI/CD, scalability, and UX for AI-driven orchestration workflows.

Build high-performance, real-time Angular frontends for AI-driven agent interfaces. Implement SSE/WebSockets streaming, complex state management with Signals/NgRx, visualizations of agent chain-of-thought, human-in-the-loop controls, performance optimizations, and collaborate with backend/AI engineers on API schemas.

Build high-performance, real-time Angular UIs for AI-driven agent workflows. Implement SSE/WebSocket streaming, complex state management (Signals/NgRx), observability dashboards, HITL controls, performance optimizations, and collaborate on API/JSON schema design with backend and AI engineers.

Design and implement high-performance Angular frontends for AI-driven interfaces: real-time SSE/WebSocket streaming, complex state with Signals/NgRx, Chain-of-Thought visualizations, human-in-the-loop controls, performance optimization, API schema collaboration, and testing.

Lead end-to-end implementation of high-fidelity, performant, and accessible frontend features for a realtime collaborative visual canvas. Translate designs into polished interactions, optimize performance and accessibility, collaborate with PMs, designers, and backend engineers, and shape frontend best practices and design systems.

Design and implement high-performance frontend interfaces and reusable component libraries for real-time telemetry. Build intuitive data-exploration UIs, optimize web performance, collaborate on API design with backend teams, write maintainable code, and participate in technical design discussions.

Lead frontend architecture and technical strategy for a collaborative work platform. Build scalable React/TypeScript applications, design systems, real-time collaboration (sync, offline, serialization), optimize performance and observability, mentor engineers, and collaborate with Product, Design, and Backend teams to deliver high-quality, maintainable user experiences.

Lead technical direction and contribute to the frontend codebase, building user-facing tools and mentoring team engineers to enhance user experiences.

Develop and maintain web application user interfaces using Vaadin and front-end technologies. Apply UI fundamentals (including Fitts' law), refactor enterprise applications, collaborate with clients, and mentor/train other front-end developers.

Build and maintain responsive, high-performance user-facing React/Next.js applications for privacy-focused web3 products. Collaborate with backend engineers, identify and fix performance bottlenecks, participate across the product lifecycle, write tested production-quality code, and iterate quickly on UX and developer-facing frameworks.

Build and maintain the company website, client-facing portal, and internal web apps. Design and structure web pages, implement UI enhancements, optimize performance and scalability, collaborate with backend engineers (Go), ensure brand-consistent design, and mentor teammates to drive product excellence.

Founding-team senior engineer to architect and build core platform components. Work with CEO/CTO to develop scalable distributed backend systems and frontend using React, Node.js and TypeScript. Implement solid coding practices, testing, CI/CD, and agile workflows while iterating rapidly in an early-stage fintech startup.

Own and evolve the front-end architecture for a high-throughput, real-time trading app using Next.js, React, and TypeScript. Build pixel-accurate, accessible, responsive UIs under strict performance budgets; optimize rendering, state management, data flow, and bundle size for sub-second interactions. Integrate with REST and WebSocket APIs, lead end-to-end feature development, set engineering standards, mentor engineers, and contribute across the stack when needed.

Early-stage frontend-focused product engineer to own web and mobile experiences (React, React Native, Expo). Design conversational AI-native interfaces for financial planning, build in TypeScript across stack, define frontend architecture and component system, use agentic engineering tools, contribute to multi-model AI orchestration, and iterate quickly with founders and users.

As a Senior Frontend Engineer, you'll build and maintain a fraud prevention platform UI using ReactJS, collaborating with backend teams and ensuring code quality through tests and CI/CD processes.

Design and implement developer-facing UI from Figma to production using Hotwire (Turbo + Stimulus) and ViewComponents. Own the dashboard, API playgrounds, docs, marketing site, and data visualization. Optimize performance and bundle size, maintain a coherent component system, and ship polished, production-ready front-end with tests and CI/CD.

The Senior Full Stack JavaScript Developer will build and maintain user interfaces using React and Next.js, integrate with Node.js backends, and guide other developers. Responsibilities include ensuring accessibility, performance, and reliability of features, engaging in code reviews, and collaborating closely with product teams.

Lead front-end architecture and hands-on development using React. Build scalable, high-performance web applications, integrate RESTful APIs, implement testing and CI/CD, optimize performance, collaborate with design and backend teams, and mentor junior engineers.

The Sr/Staff Frontend Engineer will develop new web applications, enhance UI experiences, architect solutions, and collaborate with various stakeholders to ensure a scalable and secure platform.

As a Senior Frontend Engineer, you will design and build web applications, owning major UI projects, collaborating with cross-functional teams, and optimizing performance for a seamless user experience.

The role involves designing and building internal web applications for Nebius, focusing on automating data center operations and developing user interfaces for infrastructure management.

Design and implement scalable frontend solutions using JavaScript/TypeScript and React. Drive architecture discussions, ship features with minimal guidance, maintain code quality and styling standards, collaborate across agile teams, ensure performance and scalability, and manage end-to-end feature lifecycles in a fast-moving environment.