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

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.

Build and grow Homebot applications, services, and APIs end-to-end. Use AI tooling to rapidly deliver features, create AI-driven workflows, and ship maintainable, well-tested, scalable code. Collaborate with product, design, and engineering, and instrument systems with monitoring, logging, tracing, and analytics.

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.

Build full-stack web applications and containerized microservices for defense and intelligence customers. Develop front-end and back-end services using APIs or message buses, employ observability tools, follow Agile and CI/CD practices, and collaborate on distributed teams. Must hold active TS/SCI clearance and work on-site.

Design, develop, and maintain full‑stack web applications and containerized microservices for defense and intelligence customers. Build front-end and back-end services, integrate APIs/message buses, use CI/CD, monitoring, and collaborate on distributed Agile teams to deliver mission-focused software.

Design, develop, and maintain full-stack web and backend microservices for defense/intelligence customers. Build containerized services, front-end applications, and API/message-bus integrations using observability tools and CI/CD in an Agile, distributed team environment.

Design, develop, and maintain full-stack web applications and containerized microservices for defense/intelligence customers. Build frontend and backend services, integrate APIs or message buses, use CI/CD, and collaborate on Agile teams while operating in an on-site cleared environment.

Build full-stack web applications and containerized microservices for defense/intelligence users. Develop front-end (React/Vue) and back-end services (APIs/message bus), use CI/CD, observability tools, and collaborate in Agile teams on mission-focused signal and image processing software.

Design, build, and maintain front-end and back-end components for containerized microservices supporting defense and intelligence users. Work on APIs or message-bus integrations, implement software engineering best practices, participate in CI/CD and Agile processes, and collaborate with distributed teams.

Develop full‑stack web and backend microservices for defense/intelligence applications. Build containerized services, front‑end apps, APIs/message‑bus integrations, and support CI/CD, observability, and Agile team processes.

Design, implement, and maintain front-end and back-end components for containerized microservices. Work on signal/image-processing software for defense/intelligence customers, participate in Agile CI/CD teams, and collaborate across distributed teams.

Design, build, and maintain full-stack web and backend services for defense/intelligence customers. Develop containerized microservices, frontend applications, and backend APIs/message-bus integrations. Use CI/CD, Agile practices, monitoring and logging tools, and collaborate with distributed teams. Work requires active TS/SCI clearance and US citizenship.

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.

Design and implement full‑stack, low‑latency web-based Ground Control Station and C2 systems (map-centric UIs, real-time telemetry, video streaming), lead architecture and APIs, mentor engineers, support field tests and mission deployments, and ensure interoperability with C2 standards.

Build and scale consumer-facing mobile and web applications and backend services. Own features end-to-end across frontend and backend, optimize databases and queries, integrate third-party APIs, implement algorithms for risk and transaction evaluation, improve reliability and CI/CD, and contribute to testing, monitoring, and internal tools to support customer operations.

Senior fullstack engineer to build and scale Brigit's consumer finance platform. Own end-to-end features across frontend (React/React Native/TypeScript) and backend (Java/REST/SQL), optimize database and APIs for high scale, integrate 3rd-party services, implement risk and transaction algorithms, improve CI/CD, testing, monitoring, and internal tooling to support millions of users.

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.

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

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.

The role involves leading application performance improvements across multiple platforms, focusing on measurable metrics and driving engineering standards and workflow optimization, using both hands-on coding and strategic influence.

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).

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.