Top Senior Full-Stack Engineer Jobs in Denver & Boulder, CO

Design, build, and maintain scalable backend services and APIs for commerce workflows using Python/Django. Improve reliability, performance, and observability, operate AWS deployments, work with PostgreSQL and event-driven architectures (SNS/SQS), modernize legacy systems, and support CI/CD, testing, and production troubleshooting.

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.

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.

Owner of end-to-end ecommerce features: design, implement, and maintain scalable backend services and performant React/Next.js frontends. Integrate payment gateways and procurement systems (PunchOut), mentor engineers, uphold code quality, and improve platform stability across Node.js, MySQL, and MongoDB.

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.

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.

Develop, maintain and evolve a high-scale US sports trading platform. Build React/TypeScript frontends, backend microservices, optimize SQL and performance, implement CI/CD and automated testing, mentor junior engineers, and collaborate with stakeholders and architecture teams to ensure resilience and integration.

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.

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.

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.

Join the Entefy team as a Senior Full Stack Engineer to build a scalable full stack application enhancing digital interaction for global clients.

Lead full‑stack design and delivery of customer-facing web experiences (Browse, Navigate, Preview). Own architecture, APIs, data models, rollouts, observability, on‑call readiness, and cross-team alignment, using approved AI-assisted workflows while ensuring technical quality and reliability.

The Senior Full Stack Developer will build end-to-end solutions, collaborate in a remote environment, and write technical documentation. The role requires expertise in Ruby on Rails and various programming paradigms.

Lead technical direction and delivery for the Acquisition & Onboarding full‑stack team. Build and maintain mobile (React Native/native) and web experiences, backend services at scale, and operational tooling. Drive architecture, mentor engineers, ensure reliability/monitoring/on‑call readiness, collaborate with product and design, and improve dev processes, testing, and release practices to impact conversion and retention.

Own end-to-end growth features across the stack (TypeScript/Node.js backend, React frontend) to drive acquisition, conversion, retention and monetisation. Design architecture, run A/B experiments, instrument metrics, use AI-assisted tools in engineering workflows, mentor juniors, and iterate rapidly with PMs and designers.

The Senior Full-Stack Engineer will build end-to-end features, create APIs, write requirement documents, and learn Rust while improving product experiences for users.

The Senior Full Stack Engineer will design and implement APIs with NodeJS, develop UIs with React, manage data pipelines, and deploy projects on AWS.

The Senior Fullstack Engineer will lead projects, mentor engineers, and build user-facing SaaS products using React, TypeScript, Node.js, GraphQL, and MongoDB, focusing on team collaboration and effective trade-off decision-making.

Owner of Vannevar's authentication and authorization platform: build tenant-isolated auth systems, self-service user/group/permission admin UI, tooling to visualize and validate access, feature-flag and platform management interfaces, and shared authorization capabilities across products.

Senior full‑stack engineer responsible for building production-quality Salesforce platform capabilities, integrations (MuleSoft, REST/SOAP), AI-enabled tooling (Claude plugins, MCP servers), CI/CD, and reusable libraries. Mentor engineers, run architecture/code reviews, and collaborate cross-functionally to deliver scalable, secure cloud-native solutions using Python, LWC, Apex, and AWS.

Design, develop, and deliver fullstack web solutions, optimize platforms, mentor engineers, and manage product features from ideation to launch.

The Senior Fullstack Engineer will deliver software products, collaborate with product and business teams, lead technical practices, and ensure high-velocity iteration on a mobile advertising platform.

The Senior Full-Stack Engineer will develop claims monitoring tools and backend services, collaborate with other engineers, and influence the product architecture in a health insurance startup.

Own and implement end-to-end product features across the stack (React/TypeScript front end, Ruby on Rails backend, relational DBs, GCP infra). Design APIs and data models, ensure performance and reliability, integrate AI/LLM-powered features, collaborate with product/design/clinical teams, perform code reviews, and mentor junior engineers.