Top Senior Front End Developer Jobs in Boston, MA

Lead design and build of internal web visualization tooling for ML and AV teams. Architect scalable React/TypeScript/Vue frontends, collaborate cross-functionally, drive performance and UX best practices, mentor engineers, and deliver mission-critical data-heavy UI systems.

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.

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.

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.

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.

Build and maintain production-grade React+TypeScript web interfaces for data-intensive, real-time AI products. Own end-to-end frontend features, optimize UI performance for large datasets, collaborate with design and backend teams, establish frontend best practices, improve architecture and tooling, and resolve production issues across browsers and devices.

Design and implement pixel-perfect, high-performance web applications from wireframes to production. Collaborate with designers, PMs, and engineers, iterate on architecture and best practices, explore AI/ML integrations, and contribute to a collaborative engineering culture.