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.

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.

Join as the founding full-stack engineer to extend a TypeScript React/Next.js prototype, design product features, integrate AI/OCR, write tests and infrastructure, talk to users, and iterate quickly to drive growth.

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.

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.

Work on real-world web applications across frontend and backend. Use modern frontend frameworks (React/Angular/Vue) and backend tech (Node.js, Python, Java, PHP). Integrate RESTful APIs with databases (MongoDB, PostgreSQL, MySQL), debug, test, optimize performance, and collaborate with designers and product teams while gaining hands-on mentorship.

Designs, builds, tests, deploys, and supports full-stack features for a healthcare Registry platform. Responsibilities include frontend and backend development, PostgreSQL schemas and queries, REST APIs, webhooks, third-party integrations, observability, CI/CD, production troubleshooting, and HIPAA-compliant handling of PHI. The engineer collaborates with Product, Data, and Clinical Operations in a remote startup environment.

Design, build, and maintain full-stack features across React/TypeScript frontend and C# backend. Develop APIs, optimize MySQL schemas/queries, implement caching, monitor on AWS, participate in code reviews, and collaborate with Product and Design to deliver reliable SaaS solutions.

Develop and maintain full-stack TypeScript applications using React, Node.js, and PostgreSQL. Build intuitive user interfaces, scalable APIs, and secure systems; collaborate on architecture, code reviews, testing, deployments, incident response, and infrastructure improvements. Mentor engineers, reduce technical debt, participate in Agile ceremonies, and support production systems in a remote-first environment.

Develop and maintain full-stack applications using .NET, C#, Angular, SQL Server, REST APIs, and Azure technologies. Build customer-facing and internal applications, automation tools, conversion solutions, and modernization initiatives. Participate in testing, code reviews, troubleshooting, production support, CI/CD, DevOps, and cloud initiatives while collaborating with stakeholders and mentoring junior engineers.

Build full-stack Real User Monitoring features across frontend applications, backend services, APIs, and analytical storage systems. Design high-throughput telemetry ingestion, storage, querying, data models, and indexing strategies. Develop data-heavy user interfaces, optimize performance and costs, collaborate with SDK and cross-functional teams, and own projects from design through deployment, monitoring, testing, and iteration.

Leads the technical design and delivery of full-stack web features for AI products, spanning data models, APIs, responsive interfaces, testing, deployment, cloud infrastructure, and ongoing operations. Builds and optimizes Python API applications, integrates Azure data and DevOps services, improves system reliability and performance, and supports security and CI/CD practices. Partners with product, design, data science, and machine learning teams while mentoring engineers and guiding architectural decisions.

Build and ship end-to-end product features across an author analytics dashboard, marketing site, free tools, billing, email, and AI-assisted functionality. Design data models and APIs, integrate third-party services, develop production LLM features, and maintain testing, monitoring, performance, and observability. The role includes code review, technical documentation, independent product decisions, and close collaboration with the founder in a remote-first environment.

Build and maintain Java backend services, REST APIs, and full-stack web application features. Develop frontend functionality with modern JavaScript frameworks, use Python for supporting work, and leverage AI coding tools such as Claude Code. Write tests, debug issues, support deployment and maintenance, and collaborate on design decisions, code reviews, and application quality improvements.

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.