Top Senior Full-Stack Engineer Jobs in Boston, MA

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 modernization of dtn.com as a senior full-stack engineer—improving architecture, performance, accessibility, and integrations. Build responsive front-end experiences and back-end APIs, integrate CMS/CRM/analytics, optimize conversion and SEO, and establish engineering best practices to support marketing, content, and demand-generation goals.

As a Full Stack Engineer III at Calendly, you'll develop features, scale the platform, and mentor team members while using various technologies.

The Senior Full Stack Engineer will build platform integrations, work across the full stack, shape product architecture, and collaborate cross-functionally to enhance digital experiences.

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.

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.

As a Senior Software Engineer, you'll design, develop, and maintain full-stack applications, utilizing TypeScript and modern frameworks while collaborating cross-functionally to enhance user experience and performance.

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.

The role involves building and operating core services for authentication and data privacy, owning projects end-to-end, and enhancing system reliability.

Design, build, and test APIs and services for RoadieXD; develop internal and customer-facing React tools; partner with Product and Operations to deliver scalable, reliable features; influence architecture, write maintainable code, and improve system performance and developer experience.

Lead development initiatives for SaaS products, focusing on backend architecture, frontend design, and AI/ML integrations, especially generative AI technologies.

Design and build a high-performance, AI-native web trading experience for sophisticated retail traders. Ship core trading workflows (order entry, positions, blotter, watchlists, alerts), implement trustworthy AI UI patterns, collaborate with backend engineers on low-latency contracts, and iterate quickly with users and stakeholders to deliver end-to-end product features.

Build end-to-end full-stack AI features on a Ruby on Rails backend and React frontend, design and run experiments (A/B tests and AI evaluations), implement AI infrastructure for reliable LLM inference, and iterate quickly to scale production-ready LLM-powered products.

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.

Lead design and development of full‑stack banking and investment systems using TypeScript, React, Node and GraphQL. Collaborate with cross‑functional teams, architect scalable solutions, own the product lifecycle, ensure observability and performance, troubleshoot vendor integrations, and mentor teammates to deliver reliable financial products.

Build and maintain member- and host-facing features across web and mobile. Design scalable front-end architectures, ship React/Next.js and React Native/Expo apps, use AI tooling, own features end-to-end, collaborate with product and cross-functional teams, and contribute to testing and production readiness.

The Senior Full Stack Engineer will lead quality assurance strategies, develop automation frameworks, mentor engineers, and contribute to full-stack development while leveraging AI in testing.

Lead development of a passwordless, zero-trust platform using C++. Own complex, multithreaded systems, build CI/CD pipelines, write unit tests, perform Linux administration, apply image-processing with OpenCV, and use Python for scripting and integration. Collaborate in a fast-paced environment and mentor engineers.

The Senior Full-Stack Engineer will develop and ship features across frontend and backend systems, work with various frameworks and databases, write specifications, and improve development processes.

Design, build, and scale data integrations for healthcare systems, collaborating with teams and enhancing functionality while ensuring security and quality.

Own and scale backend systems end-to-end: design, build, and deploy performant APIs and services on AWS using Node/TypeScript. Make architectural tradeoffs, ship production code frequently, establish engineering best practices, and collaborate with product teams while leveraging AI-assisted development.

Design, build, and own end-to-end features for AI-powered finance agents and agent orchestration. Implement integrations with accounting and payment platforms, create dashboards and reporting, ensure security and data integrity, make architectural choices, monitor production, and drive AI-assisted, agentic development workflows.

As a Senior Full Stack Engineer, you'll design and build high-performance web applications, manage end-to-end solutions, and collaborate with teams to enhance user experiences.

As a Senior Fullstack Engineer, you'll develop and maintain scalable APIs and web applications, engage with customers to meet their needs, and collaborate on product features to improve Layer Health's applications.