Top Senior Front End Developer Jobs in NYC, NY

Join a small founding team to build and ship a cross-platform iOS/Android social marketplace app. Implement JS-based mobile features, photo filters and video editing, translate designs to production, integrate with backend and AI services, and own the full development lifecycle in a fast-moving startup aiming to launch in 4–6 months.

Lead ownership of Belfry's React Native/Expo mobile app and React web platform; establish frontend best practices, design systems, observability, and performance standards; contribute across the full stack (APIs, backend, integrations); deploy and scale production systems; mentor engineers and promote AI-assisted development workflows.

Build and improve Belfry’s React Native and Expo mobile application and React web platform for field officers and back-office teams. Establish UI best practices, observability, and design systems; contribute to APIs, backend services, integrations, and infrastructure as needed. Help adopt AI-powered coding tools, take ownership of product initiatives, communicate technical and product ideas, and mentor engineers.

Build AI-powered frontend applications and design systems to support GTM and marketing workflows, collaborate with design and growth teams to increase qualified leads, and improve engineering processes and UX.

Build and own LangChain’s React component library and design system. Develop accessible, reusable UI components; translate design tokens and interaction patterns into code; create tooling for theming, versioning, testing, visual regression, and component discovery; and optimize build performance, bundling, dependency management, and package versioning. Collaborate closely with designers, product engineers, and platform teams to maintain a consistent, high-quality frontend foundation.

Lead frontend development across React applications, driving architecture, delivering responsive accessible UIs, promoting test-driven development, optimizing build and CI/CD pipelines, collaborating with design and backend teams, and mentoring engineers to maintain high-quality, scalable frontend systems.

Senior Frontend Designer/Developer responsible for building responsive web UIs using ReactJS, HTML5, CSS3 and ES6. Work with cross-functional teams, leverage Webpack and Adobe Creative Suite, follow Agile practices, and maintain high code standards including unit testing, documentation, and peer review.

This role involves leading web platform initiatives, mentoring senior engineers, architecting web applications, and implementing technical strategies for improved performance.

Architect and build a high-performance, low-latency trading web platform. Integrate real-time market data and execution workflows, collaborate cross-functionally on large initiatives, and deliver scalable, performant, user-focused frontend applications with strong attention to API design, tooling, and developer experience.

Lead design-focused frontend development for polished mobile apps. Ship end-to-end features, build performant gesture-driven animations, collaborate with designers for pixel-perfect UI, maintain a mature codebase, and establish automated testing and quality practices.

Lead frontend and full‑stack projects across Marimo's open-source ecosystem. Design simple, powerful editor experiences, build performant data visualizations and editor extensions, engage with the community, triage issues, and balance community needs with product roadmap.

Build and scale frontend architecture, responsive data-rich experiences, shared components, design-system standards, accessibility practices, Storybook documentation, automated quality guardrails, and frontend tooling. Contribute to backend APIs and platform improvements while collaborating with product and design teams. Mentor engineers and improve frontend quality, consistency, maintainability, and scalability across the organization.

Build and own responsive, high-performance React + TypeScript web applications. Design frontend architecture, reusable components, state management, and data-fetching. Collaborate with product and backend teams, optimize performance and accessibility, and improve developer tooling and workflows. Contribute across the stack when needed.

The Senior Front-End Engineer will develop enterprise-grade web applications using React, collaborate with UX designers and project managers, and enhance existing applications' performance.

Develop and enhance web applications using Vue.js, collaborating with various team members, and providing efficiency improvements and support for existing applications.

The Director of Front-End Engineering leads the development and evolution of a design system, ensuring usability, performance, and accessibility while mentoring teams and driving innovation in front-end engineering.

As a Front End Software Engineer, you will design, develop, and test web applications, optimize performance, and collaborate with the engineering team on projects.

The role involves building high-quality web apps, focusing on AI-powered workflows, human-in-the-loop systems, and customer needs with attention to detail.

As a Senior Front End Engineer, you will lead feature development, write code, and influence product architecture for AI-powered EMR software.

Design, build, and deliver front-end features with strong UX focus. Own technical design, coding, testing, deployment, and monitoring in a continuous delivery, microservices environment. Collaborate with Product, implement automated QA practices, and contribute to production deployments while practicing robust testing methodologies.

The Senior Frontend Engineer will develop cross-platform applications, focusing on user-friendly healthcare interfaces, ensuring performance, accessibility, and HIPAA compliance while collaborating directly with the CEO.

Design and build responsive, accessible, high-performance web interfaces. Collaborate with designers and back-end developers, write clean code, test/debug for cross-browser compatibility, and meet project deadlines.

The Senior Frontend Engineer will develop and enhance the Navigator platform using Vue.js, improve user experience, maintain CI/CD workflows, and collaborate with cross-functional teams.

Lead full‑stack engineering projects to scale document ingestion, design multi‑jurisdiction data collection, and build government‑grade security. Deliver AI‑native features across web, desktop, mobile, editors, and APIs. Ship full‑stack solutions using React/TypeScript frontend and Python/Postgres backend while ensuring scalable, extensible architectures that delight enterprise customers.

Own and architect the frontend foundation for Handshake AI Enterprise: establish component system, design tokens, engineering patterns, shared libraries, and ship production-grade UIs while collaborating with AI and platform teams to ensure scalable, maintainable, high-performance enterprise deployments.