Top Senior Front End Developer Jobs in Seattle, WA

Leads the design and development of complex frontend systems and product features using Angular and React. Architects scalable frontend patterns, improves performance and engineering velocity, drives testing and code-quality practices, and leads major technical initiatives. Partners cross-functionally with backend, product, design, integrations, and QA; makes technical decisions, mentors engineers, and advances frontend architecture and collaboration across teams.

Build and improve ClickUp’s core product experiences using Angular and React. Responsibilities include architecting reusable frontend code, collaborating with product, design, backend, integrations, and QA teams, improving performance and usability, maintaining unit and integration tests, resolving complex bugs, following state-management patterns, and mentoring teammates in a fast-paced environment.

The Sr. Front-End Full-Stack Developer will design, implement and maintain features for a commercial software platform, collaborating closely with teams and ensuring high quality through testing and operations.

The role involves architecture, design, and development of Java-based systems, overseeing projects, and advising clients. Extensive experience in Java development is essential.

As a Senior Frontend Engineer at Hive, you will build high-performance applications, work with design and product teams, and enhance user experiences using advanced web technologies.

Build scalable React/TypeScript frontends to visualize and interact with large-scale, real-time telemetry. Define data models and workflows, optimize rendering and performance, collaborate with product, design, and backend teams, and turn ambiguous requirements into intuitive, mission-critical interfaces for technical users.

Seeking a Senior Fullstack Engineer to architect and develop a customer-facing platform, bridging AI/ML systems and user features.

Build and maintain responsive, accessible frontend interfaces using React and TypeScript. Collaborate with product, design, and backend teams to launch performant, scalable UIs, create reusable component libraries, define APIs, mentor engineers, and drive frontend best practices.

As a Senior Frontend Software Engineer, you'll develop features and enhance user experience through Typescript and React, while collaborating with cross-functional teams.

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.

Design and build data-driven front-end interfaces and user flows, partner with product and data science teams to implement solutions, develop data dashboards (Power BI), and iterate based on customer feedback.

The Senior Frontend Engineer will design and implement web interfaces, ensuring performance, scalability, and maintainable code while collaborating with design and product teams.

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.

Lead frontend development for the Shopify storefront and design system. Build and extend component libraries and theme architecture, enable self-serve merchandising, partner with design and backend teams, optimize performance and accessibility, and deliver seasonal campaigns and commerce features across product lines.

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.

Build and maintain intuitive frontend web applications for data upload, search, visualization, and interactive 2D/3D geospatial tools. Collaborate with scientists to design complex visualizations, modernize the frontend stack, mentor junior developers, and implement automated UI testing and deployment pipelines.

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.

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.

As a Frontend Engineer at Clarify, you will build AI-powered interfaces, define API contracts, manage state and performance, and mentor team members while setting architectural standards.