Top Senior Front End Developer Jobs in Los Angeles, CA

Design, build, and optimize front-end features for global ticketing platforms. Provide technical guidance, write RFCs, support releases and incidents, mentor developers, perform code reviews, and integrate third-party systems while focusing on performance and scalability.

Own and build the frontend for agentic AI features: design agentic UX, streaming responses, long-running tasks, and render agent findings alongside large telemetry datasets. Optimize browser performance (Web Workers, OPFS, WebAssembly), contribute to component libraries, collaborate on APIs, and work directly with customers to translate workflows into product features.

Build and refine front-end experiences for web and mobile: onboarding, checkout, gallery features, design system and enterprise dashboard. Collaborate closely with designers and PMs, ship fast, maintain aesthetic quality, and iterate with user feedback using React, Next.js and TypeScript.

The Senior Frontend Engineer will develop and maintain front-end features, collaborate with teams, and enhance user experience while mentoring junior engineers.

As a Senior Frontend Engineer at Cinch, you'll lead the modernization and performance optimization of React-based user interfaces, collaborate with cross-functional teams, and architect scalable UI systems with a focus on AI-driven experiences.

Own and build the JTX frontend across web and mobile: real-time order books, charts, order entry, positions, wallet/signing flows. Optimize for low-latency streaming data, performance, security, and cross-platform consistency while making long-term architectural decisions and shipping rapidly.

Lead development of interactive React front-ends with Chakra UI and Mapbox, build data visualizations (Plotly/ApexCharts), optimize performance for large and real-time datasets, enforce front-end best practices, mentor engineers, and collaborate with product, design, and backend teams to deliver accessible, responsive interfaces.

Develop and maintain WordPress websites, create custom themes and plugins, ensure cross-browser compatibility, and optimize for SEO. Provide guidance on user experience and explore new technologies.

Build and maintain a polished web portal for a premium banking and travel rewards platform using React. Collaborate with designers and engineers on feature scope and product direction, participate in code and design reviews, write well-architected code, tests, and documentation, establish frontend architecture standards, and mentor team members. The role also involves database and API integrations in a fully remote startup environment.

As a Senior Frontend Engineer, you'll develop and optimize a novel open-source CAD modeling app, enhancing performance and user experience, collaborating with backend teams, and implementing robust APIs and state management solutions.

As a Senior Frontend Engineer, you'll develop responsive web UIs, collaborate with teams, maintain the design system, and improve code quality.

The Senior Angular Frontend Developer will create scalable UIs, implement features, and optimize performance in a collaborative environment, focusing on high-quality software delivery.

Build and optimize high-volume web applications using .NET, Node, React and AWS; maintain and improve existing systems; troubleshoot bugs; perform code reviews; mentor junior engineers; participate in on-call rotation; and improve scalability and performance.

Design, build, and maintain scalable, responsive web applications using React and TypeScript. Create reusable UI components, implement end-to-end tests with Cypress, optimize performance, collaborate with product/design/backend teams, participate in code reviews, mentor junior engineers, and contribute to architecture and API integrations.

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.

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.

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.

Develop and enhance user-facing features for an LLM observability platform using React and TypeScript. Build reusable components and front-end libraries, translate designs into performant UI code, optimize cross-device/browser performance, and collaborate with backend engineers and designers to improve usability.

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.

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.