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

Develop and support software, automation tools, dashboards, and alarms for cloud infrastructure, cost attribution, and cloud efficiency. Collaborate with cross-functional teams and senior engineers to design reliable systems, APIs, databases, tests, and AI agents. Contribute to architecture and automation strategies while maintaining strong security, communication, and delivery practices.

Build backend-focused Java/Kotlin APIs and data-driven product features, while contributing to React dashboards and workflows. Design scalable systems, participate in architecture and code reviews, troubleshoot production issues using observability tools, and collaborate with data, reporting, design, and product teams to launch emerging products.

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.

Lead software engineering teams developing, integrating, deploying, and maintaining full-stack mission applications for DoD and intelligence customers. Build prototypes and high-performance user interfaces, integrate APIs and independent capabilities, collaborate with military and government operators, and conduct deployment, field testing, and troubleshooting in secure operational environments. Manage customer relationships while ensuring software quality, reliability, and performance.

Develop and deploy customer-focused web, mobile, and backend applications across the full software stack. Design major features, contribute to architecture decisions, conduct code reviews, and ensure secure, high-quality implementations. Collaborate with stakeholders and cross-functional teams using Agile and SDLC practices. Manage version control, CI/CD, environments, and releases; maintain automated test coverage and perform root-cause analysis. Build and optimize relational data solutions using SQL Server, including complex queries, stored procedures, and performance tuning.

Build and maintain scalable e-commerce and marketplace features across Node.js, React, MySQL, and MongoDB. Own complex features end to end, design backend services and APIs, integrate PunchOut procurement systems, improve platform security and reliability, conduct code reviews, and mentor engineers. The role requires strong full-stack JavaScript and TypeScript expertise, e-commerce domain experience, and the ability to work autonomously on high-volume transactional software.

Build and own CRM features and workflow automations supporting sales, marketing, onboarding, and support. Develop full-stack functionality using Next.js, FastAPI, Inngest, and related technologies; partner with teams to automate workflows; create agentic solutions for enrichment and task automation; and manage features from planning through monitoring and refinement. The role requires strong web development expertise, product sense, autonomy, communication, and experience with modern JavaScript or TypeScript frameworks and orchestration tools.

Build and maintain the full-stack platform connecting Blissway hardware to drivers, partners, and agencies. Own public user surfaces, partner integrations (DMVs, mailhouses, fleet vendors, ACH), platform/deployment tooling, service infrastructure, and internal access management. Ensure secure, robust, production-ready systems and tooling that support a fast-moving, small engineering team.

Design and implement scalable full-stack applications, databases, APIs, signal-processing algorithms, user interfaces, and data visualization tools for defense and intelligence missions. Maintain and enhance operational systems, test software with real data, deploy applications to customer facilities, and support integration, testing, and operations. The role requires independent work, innovation, and collaboration across multidisciplinary engineering teams.

Design, build, and optimize scalable cloud and web software with focus on infrastructure, performance, and hardware integration for IoT devices. Collaborate with hardware teams to ensure connectivity and high availability, implement new features, and improve system efficiency.

Lead architecture and implementation of scalable web applications using NestJS and Next.js. Build and optimize PostgreSQL schemas and queries, implement responsive UIs with Tailwind CSS, integrate LangChain-driven AI features, manage authentication with Clerk, and create end-to-end tests and automation with Puppeteer to ensure launch readiness and reliable user experiences.

Implement and maintain full-stack features for a career-intelligence platform: architect NestJS/Next.js applications, manage PostgreSQL schemas and queries, build responsive UIs with Tailwind, integrate LangChain-powered AI, implement authentication with Clerk, and create end-to-end tests and automation with Puppeteer to ensure launch readiness and performance.

Design, build, and maintain production-grade .NET web applications and APIs on Azure. Own full-stack delivery from data models and SQL to front-end components, CI/CD, testing, and architecture. Collaborate with product and delivery teams, participate in code reviews, and ensure secure, observable, well-tested services.

Build and scale fullstack Growth Platform systems, including self-service marketing tools, experimentation infrastructure, and customer and event-data integrations. Develop frontend and backend features, design and consume APIs, ensure scalability and maintainability, and collaborate with marketers, analysts, lifecycle teams, product managers, and engineers. Contribute to technical design, code reviews, testing, and process improvements while supporting attribution, data activation, and customer engagement.

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.

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.

Develop and deploy a cloud-ready PostgreSQL/PostGIS database, Python REST APIs, ETL workflows, React interfaces, dashboards, and GIS visualization tools for the USGS Volcano Hazards Program. Ensure accessibility, security compliance, documentation, testing, and interoperability across volcano observatories. Collaborate with government stakeholders, support federal certification activities, and participate in up to three onsite visits during the 12-month engagement.

Leads technical vision and strategy for Affirm’s Marketplace, Search, Ads Platform, and consumer experiences. Designs scalable full-stack platforms, guides architecture and technical excellence, coordinates initiatives across engineering teams, mentors engineers, and drives reliable delivery of customer-focused products across iOS, Android, and Web.

Build, maintain, and deploy a high-volume, fault-tolerant observability platform. Architect and develop OpenTelemetry-based systems, implement services in Go (concurrency/gRPC), work with ClickHouse/Postgres, Kafka/Redis streaming, and containerized deployments on Kubernetes/Docker. Evaluate new tools and improve platform reliability and performance.

Develop and sustain full-stack applications supporting DISA’s IDEAS system in a secure DoD environment. Responsibilities include Java and JavaScript development, database and web-service integration, cloud deployment, testing, troubleshooting, Tier 2/3 support, root-cause analysis, documentation, and Agile/Scrum collaboration. The role also supports cybersecurity standards, release activities, configuration control, system monitoring, and integration with DoD and federal systems.

Develop cloud-native, full-stack applications for Nelnet’s lending platform using microservices and modern JavaScript technologies. Responsibilities include collaborating with product and design teams, designing and coding application and infrastructure solutions, implementing testing and CI/CD processes, managing cloud environments, building REST APIs, and participating throughout the software development lifecycle. The role emphasizes scalable, high-quality code, architectural contribution, Agile practices, and continuous improvement.

Designs and develops complex full-stack software systems using Java, JavaScript, Angular, Spring Boot, AWS, and related technologies. Provides technical leadership, mentorship, code reviews, and innovation while collaborating with business partners, architects, analysts, engineers, and technical leads. Translates business logic into technical requirements, works in an Agile Scrum environment, and creates developer-facing technologies and documentation.

Develop, enhance, test, deploy, and support full-stack enterprise applications in AWS. Build front-end interfaces, backend services, REST APIs, integrations, and database components. Contribute to architecture and technical design, troubleshoot complex production issues, participate in code reviews, and support automated testing, CI/CD, Agile planning, and deployment activities. Collaborate with Product, QA, Cloud/DevOps, and engineering teams while following secure coding and software development standards.

Build and operate high-scale internationalization infrastructure, including translation workflows, APIs, UIs, libraries, and platform tooling. Improve legacy systems through migrations while enhancing reliability, observability, latency, security, and cost efficiency. Prototype and productionize machine-learning and large-language-model capabilities, collaborate across engineering and business teams, and deliver measurable improvements in quality, adoption, developer productivity, and operational efficiency.

Develop and deploy full-stack applications using Java, Spring, Angular, Oracle, and Azure. Responsibilities include building REST APIs and microservices, optimizing database performance, troubleshooting across the stack, participating in architecture and code reviews, and collaborating with QA, DevOps, UX, and product teams.