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.

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 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.

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).

Responsible for leading a team of engineers, supporting product development, identifying technical issues, and ensuring high-quality code delivery in backend systems at scale.

Design, build, and maintain cross-platform mobile applications and end-to-end web features. Implement front-end interfaces, back-end services and RESTful APIs, optimize databases, write tests and documentation, perform code reviews, and collaborate with UX, QA, and DevOps to deliver high-quality, secure, and performant solutions.

Build and maintain scalable React/Node/TypeScript web applications, design RESTful APIs and microservices, optimize performance, troubleshoot full-stack issues, collaborate on features, adopt AI-assisted tools, and support CI/CD and cloud integrations.

As a Full Stack Engineer, you'll develop secure features, integrate data pipelines, design APIs, and collaborate closely with teams to enhance healthcare technology.

The Full Stack Engineer will design, implement, and deliver full-stack features, focusing on scalable APIs and cloud-native solutions while collaborating with clients and engineering teams.

The Full Stack Developer will develop and deliver web applications, integrate APIs, and work with both front-end and back-end technologies. The role demands strong problem-solving skills and the ability to work under tight deadlines with minimal supervision.

As a Full Stack Engineer, you will build AI-powered applications, manage client interactions, and apply best practices in MLOps and LLMOps.

The Jr. Full Stack Developer supports application modernization by designing and developing web-based applications using React and Spring Boot in an Agile environment, ensuring quality and efficient coding processes while collaborating with teams and documenting solutions.

Full-Stack Engineers at CapTech design and develop enterprise systems, collaborate with clients, and mentor peers while utilizing up-to-date technologies.

The Full Stack Engineer will build cloud-based applications, collaborate with teams, and utilize AWS technologies to deliver solutions.