Top Senior Full-Stack Engineer Jobs in NYC, NY

Build and maintain React + TypeScript front-end applications, create prototypes, contribute reusable components and tests to shared libraries, integrate APIs and data services, and collaborate with designers, product, data scientists, and engineers to deliver data-driven decision intelligence products.

Lead technology projects and a developer team, create solutions meeting regulatory needs, and deliver cloud-based solutions for financial empowerment.

Lead and deliver cloud-based, full-stack microservices solutions; manage a portfolio and mentor engineers; collaborate with product managers; design and implement systems using modern languages, containers, and cloud services to meet regulatory and customer needs.

As a Senior Software Engineer, you will design and build a cutting-edge identity search platform and implement AI systems for defense applications, working closely with cross-functional teams to enhance user workflows and support national security.

Build and own complex frontend features using Vue 3 and TypeScript while developing the Python services and APIs that power them. Improve performance, accessibility, testing, CI/CD, and observability; collaborate with product and design; mentor engineers and apply AI-assisted development tools responsibly to accelerate productivity and maintain quality and security.

Design and implement scalable backend services for payment and transaction workflows using Java. Own end-to-end features from data model and APIs to Angular frontends, improve reliability and performance, refactor legacy systems, troubleshoot production issues, and collaborate with product and design. Leverage AI-assisted development tools responsibly and share best practices across the team.

Seeking a Senior Software Engineer with 7+ years of experience, proficient in Rails and Python, to develop applications and shape engineering culture.

Responsible for leading a team of engineers, supporting product development, identifying technical issues, and ensuring high-quality code delivery in backend systems at scale.

Develop fullstack web applications, enhance platform performance, collaborate on high-impact opportunities, and ensure stable, scalable solutions. Engage in rapid iterations and be a committed team player.

As a Senior Full Stack Engineer, you will design and develop scalable APIs, integrate financial data, and enhance user experience in a collaborative environment.

Lead a team to design and build AI-native engineering harnesses and agentic workflow orchestration for governed model use. Implement typed contracts, observability, CI/CD integration, evaluation gates, developer tooling, and cloud-native services to enable secure, auditable, and repeatable AI-assisted software delivery across the enterprise.

Lead full‑stack teams to design and deliver cloud-based, microservices solutions. Mentor engineers, collaborate with product managers, and build scalable systems using Python, ReactJS, AWS, containers, and modern data tools to meet regulatory and customer needs.

Lead a portfolio of full-stack, cloud-based projects and mentor engineers to deliver microservices and regulatory solutions. Collaborate with product managers, design robust AWS-based systems, and occasionally write or evaluate code.

Lead design and implementation of the PSA Liquidity Platform connecting buyers and sellers. Build buyer tooling, matching/ranking engines, and seller experiences. Architect and operate microservices and Kafka-driven systems on Kubernetes/AWS, instrument observability, apply AI tooling across the SDLC, and drive cross-functional delivery from 0-to-1 while owning end-to-end outcomes.

Lead design and build of an enterprise AI content platform: RAG-backed knowledge library, embedding search pipeline, prompt MLOps, validation/critic pipelines, shared platform APIs, architecture and mentorship for production LLM systems.

Design and build agent-powered mission consoles, collaborate with stakeholders to improve user workflows, and maintain agentic workflows for mission outcomes.

The Senior Full-Stack Engineer will manage client relationships, design integration solutions, and ensure seamless delivery and optimization of technical workflows, while leveraging AI for efficiency.

Build and ship full-stack features for customer-facing Console and Playground, plus internal tools. Design and maintain APIs and backend services, implement accessible performant frontends, translate product requirements into incremental work, and improve code quality through reviews and design discussions.

Design, build, integrate, and support scalable Wealth Management full stack applications. Implement responsive React front-ends and secure C#/.NET backend services, design RESTful APIs, integrate enterprise systems (MuleSoft, vendor APIs, data platforms), use AWS cloud services, apply DevOps practices, and leverage AI-assisted development tools to accelerate delivery.

The Senior Lead Software Engineer will lead diverse technology projects, collaborate with product managers, and deliver cloud-based solutions while mentoring other engineers and utilizing various programming languages and technologies.

Build end-to-end full-stack AI features on a Ruby on Rails backend and React frontend, including LLM inference infrastructure, RAG, AI agents, and evaluation/observability. Design and run experiments (A/B tests), optimize systems for production performance and reliability, and iterate rapidly with product and design partners.

Own end-to-end projects building scalable web and backend services for millions of members. Develop frontend experiences with React, Next.js, and React Native; build backend services with Node.js frameworks; design schemas and optimize PostgreSQL queries; implement observability; participate in architecture, code reviews, and production support.

Build and evolve Circle Discover marketplace features: high-converting purchasing flows, algorithmic recommendations, content feeds, and listings. Work across a Ruby on Rails backend and React/Next.js front-ends, optimize performance and SSR/SSG, collaborate with designers and leaders, and improve codebase quality while shipping at pace in a distributed remote team.

Develop and deliver production-ready web experiences for marketing using React, Gatsby, and Tailwind. Build API integrations, maintain a lightweight codebase and design-system components, ensure accessibility, performance, SEO, and multi-region support, participate in code reviews, and help shape tooling and best practices across the team.

As a Senior Software Engineer, you'll implement collaboration features, support team architecture, work across tech stacks, and improve developer experience.