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

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.

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.

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.

Lead end-to-end development of customer-facing product experiences and backend systems across frontend and backend layers. Design scalable services, APIs, and data flows; improve accessibility, performance, reliability, security, observability, and maintainability. Partner with Product, Design, Data, and engineering leaders to deliver complex initiatives, influence architecture, support incident response, mentor engineers, and connect technical decisions to customer and business outcomes.

Build and operate end-to-end product capabilities across frontend and backend systems. Develop accessible React and TypeScript experiences, backend services and APIs using Go, Python, or similar languages, and scalable data flows. Translate customer and product needs into technical designs, own features through launch and iteration, improve observability and reliability, and collaborate with Product, Design, Data, and Engineering teams.

Lead full-stack software development across frontend and backend systems, delivering user-facing healthcare features from concept through iteration. Design APIs and application architecture, write technical specifications, improve testing and CI practices, collaborate with product, AI/ML, clinical, and UX teams, and guide cross-team technical decisions. The role involves React, Python, cloud infrastructure, databases, asynchronous workflows, and healthcare data technologies.

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.

Provides technical leadership for AI Trust and Governance engineering, designing scalable cloud-native services and distributed systems. Responsibilities include architecture, systems programming, concurrency, testing, debugging, deployment, release management, cross-team collaboration, and mentoring engineers. The role requires strong Java or C skills, expertise in distributed systems and consensus algorithms, and ownership of enterprise platform features from design through delivery.

Build, test, deploy, monitor, and maintain web applications and enterprise CMS platforms. Develop full-stack solutions using C#/.NET, JavaScript, SQL, and related web technologies while supporting Kentico, SharePoint, and Salesforce. Troubleshoot web servers and technical issues, integrate APIs and web services, manage cloud-hosted systems, and collaborate with business teams, consultants, and nontechnical users. Apply web security, accessibility, responsive-design, testing, and application lifecycle best practices.

Lead frontend and full-stack engineering, architect scalable features, integrate APIs and cloud services, optimize rendering and performance, establish engineering standards, conduct code reviews, and mentor developers. Collaborate with product, UX, and backend teams to deliver user-focused software while managing priorities in an ambiguous environment.

Work on front-end and back-end web projects: create and redesign websites, build sitemaps and wireframes, collaborate with teams, and focus on UI/UX and performant back-end functionality.

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.

Develop full-stack features for secure OPIR research and development systems. Build front-end interfaces, backend microservices, APIs, containerized services, cloud deployments, and DevSecOps automation. Integrate data, analytics, and ML pipelines into mission workflows while supporting legacy modernization. Participate in Agile ceremonies, code reviews, troubleshooting, user-centered design, and engineering improvements. The role requires an active TS/SCI clearance, STEM bachelor's degree, and at least four years of full-stack development experience.

Lead the architecture and delivery of cloud-native, full-stack GEOINT systems and microservices. Develop secure distributed applications, govern AWS and Kubernetes deployments, build DevSecOps pipelines, integrate data and analytics platforms, guide modernization and technical roadmaps, mentor engineers, and partner with mission users. The role requires active TS/SCI clearance and supports classified environments.

Build end-to-end full-stack features using modern front-end frameworks, backend microservices, APIs, containers, cloud platforms, and DevSecOps pipelines. Support legacy pipeline modernization, integrate data and ML components, troubleshoot across the stack, and collaborate in Agile delivery through planning, reviews, testing, and user-focused design. The role requires an active TS/SCI clearance, STEM bachelor’s degree, and experience with cloud deployment, databases, CI/CD, Docker, Kubernetes, and full-stack development.

Lead the architecture, modernization, and implementation of secure, cloud-native GEOINT applications and microservices. Develop scalable backend services, govern AWS and Kubernetes deployments, implement DevSecOps pipelines, integrate data and search platforms, and guide technical roadmaps. Partner with mission users and engineering teams, mentor developers, conduct code reviews, and evaluate AI technologies. The role requires experience with distributed systems, APIs, databases, cloud infrastructure, classified environments, and an active TS/SCI clearance.

Leads end-to-end engineering across client engagements, including architecture, development, deployment, maintenance, and technical client relationships. Builds web applications, APIs, integrations, and CMS solutions while establishing development workflows, CI/CD pipelines, and engineering standards. Facilitates technical discovery, reviews code, manages technical debt, and evaluates AI-assisted development practices. Collaborates with designers, strategists, project managers, and QA while balancing quality, budgets, timelines, and evolving priorities.

Develop and deploy life-saving technologies as a fullstack engineer, focusing on web applications for public safety, collaborating with various engineering disciplines and leveraging customer feedback.

Own full-stack modernization of complex federal legacy systems using Java, Spring Boot, RESTful APIs, React, and relational databases. Analyze workflows, distinguish essential functionality from process overhead, design scalable applications, build integrations, support the full software development lifecycle, troubleshoot across application layers, and collaborate with technical and non-technical stakeholders in an Agile environment.