Top Senior Full-Stack Engineer Jobs in Boston, MA

Build end-to-end features, design intuitive interfaces, manage asynchronous backend jobs, and contribute to open-source efforts, while leading project development from concept to monitoring.

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.

The Senior Full Stack Software Engineer will oversee technical development in a B2B SaaS healthcare environment, mentor junior engineers, and lead product features.

Design, build, and deploy scalable contracts management features using Python and AWS. Collaborate with teams to implement backend services and maintain a growing React project.

Deliver and scale full‑stack product features end-to-end: design and implement frontend and backend systems, align architecture, collaborate with product/design/data/QA, estimate work, ensure SDLC quality, communicate status, and participate in on-call rotation.

Lead full-stack product engineering for AI-powered healthcare features. Build frontend experiences, backend services, APIs, relational data models, and AI workflows. Prototype, ship, and iterate production systems; improve AI via evaluation and product signals. Ensure reliability, privacy, observability, and operational readiness while collaborating with product, design, customers, and engineers.

Design, build, and ship full-stack features across mobile (Vue/TypeScript/Capacitor) and backend systems (Python/Flask/Postgres/Redis/AWS). Drive architecture, partner with Product and Design, decompose ambiguous problems into iterative work, participate in on-call rotation, and mentor through design and code reviews to support millions of users accessing government benefits.

Lead end-to-end design, development, and delivery of full‑stack features; drive architecture and code reviews; coordinate engineering work, write design docs and tests, and participate in Agile ceremonies. Must have blockchain/crypto experience.

The Senior Fullstack Engineer will build foundational product features and integrations to drive user acquisition, optimization, and monetization at LangChain, collaborating with various teams for growth.

Lead the technical architecture and implementation for LangSmith, collaborating with teams, mentoring juniors, and ensuring code quality.

Lead automation solutions development, manage integration for business applications, and ensure system performance and security. Provide technical guidance and support for junior developers.

Design and build omnichannel advertising systems, integrate team capabilities, mentor engineers, and handle end-to-end project ownership.

Build and own end-to-end product features across React/TypeScript frontend, Ruby on Rails backend, relational databases, and GCP/AWS infrastructure. Partner with product, design, clinical, and operations teams to translate complex healthcare workflows into simple experiences. Improve reliability and performance, mentor engineers, raise engineering standards, and integrate AI-powered features into production.

Build, ship, and maintain full-stack features for North: large-scale file uploads, shared knowledge bases, agent extensibility, and data-sync pipelines. Own end-to-end design, implementation, testing, launch, and iteration while working closely with Product, UX, and modeling teams. Prioritize security, performance, and mentoring.

Build and maintain full-stack features for a React/TypeScript frontend and NestJS/TypeScript backend, integrate LLM-powered conversational agents, design APIs, auth (SSO/SAML), real-time updates, background processing (AWS SQS), database schemas (PostgreSQL/Sequelize), API docs (Swagger), and tests (Jest/pytest). Collaborate on architecture, code review, and production support.

Embed with brokerage operations to observe and automate manual workflows; design, build, deploy, and monitor auditable backend services and UIs; measure impact with operations metrics; produce RFCs; collaborate with compliance/security; own CI/CD, on-call, and incident response for production systems.

Lead design, development, and implementation of full-stack applications using .NET and Angular. Collaborate with teams to gather requirements, ensure security, scalability, and performance on Azure, manage SQL Server databases, use Git for version control, and mentor engineering teammates while adopting best practices and emerging technologies.

Design, build, and maintain backend services in TypeScript for millions of users; develop full‑stack features with React/React Native; participate in code reviews; provide technical leadership, mentorship, and architecture guidance; collaborate with PM and design; use monitoring/metrics and Agile practices to deliver scalable, user-focused products.

Lead backend TypeScript development and maintain services used by ~5M users. Contribute to full-stack features, code reviews, architecture discussions, mentor engineers, and collaborate with PM/design to build React-based web and mobile experiences.

Senior Full Stack Developer for Nexamp will build and optimize internal financial modeling tools using a React/Django/Azure stack, own architecture and delivery, mentor junior engineers, collaborate with stakeholders, and improve processes to scale deployment of solar power projects.

Lead design and implementation of cloud-first, AI-integrated full-stack applications on GCP. Drive rapid prototyping and MVPs, mentor developers, define architecture, maintain CI/CD pipelines, and collaborate cross-functionally to deliver production-ready solutions.

Senior .NET full-stack developer responsible for custom application development, API integrations, database optimization, deployments, troubleshooting, performance, security, and production support using .NET/C#, ASP.NET Core, SQL, modern frontend frameworks, cloud, and CI/CD.

Lead full‑stack development of the imaging web platform: architect and build ASP.NET Core services and Vue frontends, design secure APIs integrating EMRs and AI, own testing, CI/CD, and Azure deployments, mentor engineers, and collaborate with product, design, and clinical teams to deliver performant, reliable screening experiences.

Lead design and delivery of full-stack imaging features, architect high-performance ASP.NET Core services, build Vue frontends, integrate APIs with EMRs and imaging partners, mentor engineers, enforce automated testing, CI/CD and observability, and drive technical roadmap in an Agile team.

As a Senior Fullstack Engineer, you'll develop end-to-end features for Cart & Checkout, collaborating with cross-functional teams. You will design full-stack solutions and ensure quality through documentation and monitoring, while also mentoring junior engineers and optimizing systems for performance.