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.

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.

Design, develop, test, deploy, and support scalable full-stack cloud-native applications using Java, Spring Boot, Vue.js, Python, and FastAPI. Build secure APIs and operate AWS applications with Docker, Kubernetes, and Infrastructure as Code. Collaborate with product, systems, and architecture teams to deliver features end to end. Apply AI-assisted development throughout coding, testing, debugging, code review, and documentation while validating quality, security, and maintainability.

Leads technical direction and develops fullstack purchase experiences using Ruby on Rails and Vue.js. Designs resilient transactional flows, integrates billing and CRM systems, improves reliability and rollout safety, mentors engineers, reviews code, reduces technical debt, and participates in incident response. Partners with Product, Design, Billing, and Support to improve GitLab’s purchase, subscription, discount, and upgrade workflows.

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.

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.

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.

Build and maintain end-to-end features across backend (Node.js/TypeScript, Python) and frontend (React/TypeScript). Model Postgres schemas, integrate queues (QStash/Upstash), deploy on Cloudflare edge, write tests, enforce CI/CD, and harden systems for security and performance in regulated environments.

Build end-to-end user features under senior guidance: implement REST endpoints in Node.js/TypeScript, microservices in Python, maintain PostgreSQL schemas, process background jobs with QStash/Upstash, deploy to Cloudflare Workers/Pages/R2, write tests, and collaborate with product/design on React UI components.

Own fullstack development for Broad Arrow Auctions across customer-facing auction experiences and internal live-auction tools. Build scalable web applications, APIs, integrations, automated tests, and cloud infrastructure using Azure and AWS. Maintain Billboard auction software, integrate Microsoft Dynamics 365, monitor production systems, participate in on-call support, contribute to architecture, improve reliability and performance, and mentor less experienced engineers.

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.

Own end-to-end full-stack feature development across React/TypeScript interfaces and Elixir backend services for spacecraft modeling, simulation, and ground-control software. Drive architecture, technical debt reduction, performance, reliability, testing, API design, and production deployment. Mentor engineers, establish coding standards, collaborate with product, design, QA, operators, and astrodynamics teams, and deliver complex data-dense, real-time applications.

Build and scale full-stack applications, backend services, APIs, infrastructure, and user experiences supporting millions of users. Design reliable, high-performance systems; partner with Product, Design, and Data; own projects through deployment and optimization; improve observability and developer productivity; and support AI adoption through automation and AI-powered workflows.

Lead full-stack software development from design through delivery for Judi Health’s healthcare benefits platform. Partner with product, design, and QA teams to define requirements, build scalable features, provide technical leadership and support, and expand the platform using Python, AWS, React, TypeScript, and PostgreSQL in an Agile/Scrum environment.

Build and enhance scalable web-based healthcare platform applications using Python, React, AWS, and related technologies. Responsibilities include implementing features, writing and testing maintainable code, debugging, collaborating with product and design teams, participating in Agile/Scrum planning, and delivering cloud-based microservices and API applications throughout the software development lifecycle.

Contribute to full-stack features for spacecraft mission control and distributed ground control systems. Build React/TypeScript frontends and Elixir backend services, write maintainable and testable code, collaborate with operators, designers, and engineering specialists, and participate in design and code reviews. The role involves smaller, well-defined tasks under senior guidance during a three-month temporary engagement with potential conversion.

Build and own user-facing features and core platform architecture across frontend, backend, and ML pipelines. Integrate AI workflows (LLMs, embeddings) for curriculum generation and automated evaluation. Manage end-to-end development: requirements, design, implementation, CI/CD, testing, observability, and iteration while collaborating with product, design, ML, and customer teams.

Develop and deploy scalable Java microservices and serverless applications using Spring Boot, AWS EKS, and AWS Lambda. Build RESTful APIs, integrate Vue.js front ends, write automated unit tests with JUnit and Mockito, manage CI/CD pipelines, and maintain Git workflows. Preferred experience includes SQL and NoSQL databases, Docker, and monitoring tools for Kubernetes environments.

Leads architecture, design, development, deployment, and technical direction for cloud-based SIGINT microservices. Collaborates with customers, analysts, systems engineers, and software teams using Agile methods. Develops Java/Spring back-end services and modern front-end applications, works with databases and containerized cloud systems, and manages CI/CD pipelines. The role requires active TS/SCI clearance with CI polygraph, technical roadmap ownership, and participation in quarterly customer reviews involving approximately 10% travel.