Top Senior Javascript Jobs in NYC, NY

Evaluate AI coding-agent interactions for usefulness, correctness, engineering judgment, explanation quality, and user trust. Provide rigorous, opinionated feedback distinguishing response quality levels and help define best practices for tools such as OpenAI Codex, Claude Code, and Cursor. This contract role requires experienced software engineering judgment rather than production coding.

Design and build AI-centric full‑stack TypeScript web applications (SPAs and APIs). Collaborate on product and architecture, own technical decisions, mentor peers, perform code reviews, and manage project priorities and deliverables.

Develop and maintain high-scale JavaScript and TypeScript monetization solutions using Prebid.js, Prebid Server, and Google Ad Manager. Own the header bidding wrapper, integrate auction and ad-tech standards, optimize Core Web Vitals and client-side performance, operate Google Cloud services, review code, document architecture, and resolve production issues.

Build end-to-end features in a JS/TS stack, designing scalable backend services and responsive real-time frontends. Improve observability, performance, and reliability, collaborate with product/design, and own full-stack implementation from APIs and data models to UI.

As a Senior Full-Stack Software Engineer, you will develop AI-centric web applications, participate in architectural decisions, and mentor team members while managing project priorities and deliverables.

The role involves leading the development of a high-performance Web SDK for fraud detection and risk management, implementing algorithms for device fingerprinting, and ensuring security and performance optimization.

Join a team building a strategic reference data platform for client, account and instrument data. Deliver horizontally scalable, high-performance JavaScript applications, collaborate with senior business and technical partners, and maintain/extend mission-critical software. Requires strong problem-solving, independence, and ability to learn new technologies quickly.

The role involves developing scalable web-based UIs and trading tools, collaborating with traders and developers to implement trading and reporting tools.

As a JavaScript Developer, you will design, implement, and maintain web applications, collaborate with cross-functional teams, innovate solutions, and ensure high performance and availability of systems.

Senior full‑stack engineer responsible for building backend services (Node.js/TypeScript) and integrating with frontends (React/Vue). Ship production APIs, collaborate cross‑functionally, own delivery, mentor peers, and develop modular, testable, performant systems across diverse greenfield projects.

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 Supabase JS/TS SDKs used across runtimes. Author libraries, manage public repos, triage issues, review PRs, keep CI/release automation healthy, own type experience, support realtime/WebSocket semantics, ensure cross-runtime compatibility, write RFCs, docs, and migration guides, and improve SDKs for AI coding agents.

Build and maintain the SaaS product, data pipelines, AI agents, and telemetry; contribute to product and tech strategy; work with customers; set engineering best practices and mentor teammates.