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

The Full Stack Engineer will develop features for a dynamic web application, collaborate with team members, enhance performance, and improve automated tests.

As a Fullstack Engineer, you'll design, build, and operate web applications, collaborating with product teams and mentoring peers while ensuring best practices in coding and system architecture.

Build and maintain FareHarbor.me, a managed WordPress site platform. Develop PHP and JavaScript features, craft themes/plugins and Gutenberg blocks, collaborate with design and product, review PRs, write docs, and improve accessibility, performance, and editor UX across thousands of client websites.

Build and own end-to-end full-stack features across backend services and user-facing applications. Contribute to system design, reliability, performance, observability, and engineering practices while collaborating with product and design.

Lead full-stack mission engineer who designs, develops, integrates, and deploys software for DoD/IC missions. Lead cross-functional teams to build high-performance frontends and cohesive systems, collaborate with military customers for product discovery, and deploy and field-test solutions in secure operational environments (travel ~1 week/month).

Design, build, and maintain front-end visualizations and back-end web services for real-time geospatial data. Participate in full software lifecycle, ingest GIS/imagery data, improve tools/processes, and collaborate on modern web frameworks and performance profiling.

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.

Modernize a large fintech platform by building NestJS services and Next.js UIs, migrate transactional data to relational schemas, write comprehensive tests, identify and fix legacy problems, design scalable solutions that coexist with legacy systems, and use AI tooling responsibly to increase engineering velocity.

Seeking a full stack engineer to develop applications, requiring skills in Node.js, SQL, and modern JavaScript frameworks with a focus on scalability and performance.

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 and implement full stack features for a healthcare platform, focusing on both frontend (React) and backend (Node.js) development. Responsible for performance optimization, API creation, testing, and collaboration with data engineering teams.

Volunteer Principal Full Stack Engineer to lead and contribute across frontend and backend (React/React Native, Node.js, MongoDB). Own feature development, mentor engineers, collaborate with product/design, ship scalable code, and support CI processes. Must commit 4+ hours weekly and attend a weekly standup; first task includes launching a fundraising campaign.

Build and maintain frontend and backend components for a health services platform. Develop responsive UIs, design and integrate REST APIs, optimize performance and security, participate in code reviews, troubleshoot issues, and collaborate in an Agile team to deliver features.

Lead and deliver software solutions, oversee full-stack architecture, mentor engineers, and drive cross-functional initiatives for spacecraft modeling and control platforms.

Build and ship end-to-end features for a restaurant operating system, lead architecture and technical execution, define product roadmap with cross-functional teams, and maintain high-quality CI/CD and productionized systems.

The Full Stack Engineer will design, build, and maintain scalable web applications, impact customer onboarding and integrations, write and review code, and support technical improvements.

Build and maintain data-intensive, interactive web products across the full stack. Architect and implement API and frontend features, validate FastAPI responses with Pydantic, access Postgres via SQLAlchemy, optimize performance and scalability, implement testing and QA, participate in code reviews, refine UX, and help define engineering processes at an early-stage company.

Build end-to-end features across frontend and backend using React/TypeScript and Node.js (some legacy Go). Collaborate with design, ship via continuous deployment, debug and monitor production, use AI coding tools, and make product and technical decisions while owning delivered features.

Design, build and maintain Microsoft Cloud applications using Power Apps/Pages and Azure services. Implement Entra ID authentication, Azure Functions/App Services, Logic Apps and Blob storage. Create Azure Data Factory pipelines and APIs (REST/GraphQL), integrate external services and LLM data pipelines, and ensure performance, security, and scalability while collaborating with customers to turn requirements into streamlined apps.

Build and maintain end-to-end product features across frontend, backend, and databases. Design APIs, authentication, data models, integrations, and AI-assisted workflows. Ship production-ready SaaS components, debug across the stack, improve reliability and performance, and collaborate on product and architecture decisions in an early-stage startup.

Design and implement backend features in Go, build data pipelines and REST APIs, work with PostgreSQL and AWS, contribute to scalable system design, and optionally develop React.js user-facing features while collaborating in a fast-paced AI-focused startup.

Full-stack engineers will develop features for a system used by radiologists, focusing on low-latency WebSocket workflows and UI/UX design.

Build and maintain Django-based web applications, design RESTful APIs, implement frontend features (HTML/CSS/JS), optimize performance and security, collaborate with cross-functional teams throughout the development lifecycle.

Build and scale a fintech platform across accounting, tax, and banking. Own feature lifecycle from design to deployment, write backend and frontend code, improve infrastructure and reliability, and collaborate with product and design to deliver customer-focused features.

Work on real-world web applications across frontend and backend. Use modern frontend frameworks (React/Angular/Vue) and backend tech (Node.js, Python, Java, PHP). Integrate RESTful APIs with databases (MongoDB, PostgreSQL, MySQL), debug, test, optimize performance, and collaborate with designers and product teams while gaining hands-on mentorship.