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.

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.

Join a small team to improve a tech product aimed at upskilling users in MENA, working with JavaScript and Node.js in a collaborative remote environment.

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.

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.

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.

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.

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.

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.

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 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 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.