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

Build and launch scalable fullstack web applications and APIs for Affirm’s Ads Platform. Collaborate with product, design, analytics, and engineering partners to break projects into deliverable phases, make technical trade-offs, write tested and extensible code, monitor service metrics, support on-call operations, review code, and participate in team development and interviews.

Build and ship full-stack web and mobile experiences across Affirm’s consumer products. Break down projects, collaborate with product, design, and analytics teams, develop scalable APIs, write well-tested code, monitor service health, participate in on-call support, review code, and contribute to engineering growth and interviewing.

Lead design and delivery of full-stack basketball scoring, statistics, and postgame features. Build scalable backend services and APIs with TypeScript and Node.js, develop React web experiences, support iOS and Android products, and make architectural decisions. Collaborate across product, design, and engineering teams, ensure code quality and system reliability, mentor peers, and contribute to technical standards and tools.

Lead the architecture and delivery of GitLab’s data products, including near-real-time data ingestion, knowledge graph integrations, data marketplaces, observability, and data-sharing APIs. Translate ambiguous 0-to-1 initiatives into roadmaps, resolve cross-team dependencies, ensure operational readiness across deployment surfaces, and mentor engineers. The role requires deep full-stack expertise, technical leadership, and experience with AI-powered orchestration and multi-tenant SaaS systems.

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.

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.

Design, build, and deploy secure, high-performance, scalable cloud-native applications supporting Ariba P2P. Work full-stack in Java using Spring Boot and the SAP BTP Cloud Foundry CAP (Java) model, applying resiliency, security, and performance best practices.

Designs, develops, and deploys enterprise applications using Java, Spring Boot, microservices, REST APIs, cloud services, databases, DevOps tools, and Angular or React. The role also involves AI exposure with Python, LangChain, and LangGraph, along with application security, monitoring, performance, deployment, and collaboration with project teams. The position is onsite in McLean, Virginia.

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.

Design, implement, and optimize full-stack solutions. Collaborate with cross-functional teams, participate in code reviews, analyze and improve system performance, and stay current with industry technologies.

Own backend services and frontend experiences across signup, onboarding, verification, activation, checkout, and customer lifecycle management. Build event-driven systems, integrate identity and risk providers, handle sensitive financial data, run experiments, and analyze funnels using SQL and Snowflake. The role also involves evaluating AI-generated code, analysis, and customer messaging while collaborating with Product, Data, and Risk in an ambiguous, high-ownership environment.

Own end-to-end product features for a SaaS platform serving HR, therapists, and employees. Build, scale, and evolve frontend and backend components, lead architecture and standards, collaborate with design and product, and incorporate customer feedback and QA. Work in an early-stage startup environment with product-focused ownership.

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 end-to-end features in a JS/TS stack, designing scalable backend services and responsive real-time frontends. Improve observability, performance, and reliability, collaborate with product/design, and own full-stack implementation from APIs and data models to UI.

Design, implement, and maintain scalable serverless backend services and responsive Next.js front-end components. Build data scrapers and integrations, improve CI/CD and IaC, mentor junior engineers, and collaborate with product and clients to solve complex compliance problems.

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.

Lead end-to-end design, development, and delivery of full‑stack features; drive architecture and code reviews; coordinate engineering work, write design docs and tests, and participate in Agile ceremonies. Must have blockchain/crypto experience.

Join as an early founding full-stack engineer to architect, build, and deploy a scalable platform serving AI-driven voice applications. You will own frontend and backend development, design infrastructure with the CTO, and deliver reliable production systems for enterprise customers.

Build and maintain core products and collaborate on larger consulting projects using TypeScript, Python, FastAPI, Next.js, GCP, and generative AI frameworks. The role involves hands-on software development within a rapidly growing, remote team serving Saudi Arabia and the GCC.

Build and ship end-to-end features for a restaurant operating system, lead architecture and technical execution, define product roadmap with cross-functional teams, and maintain high-quality CI/CD and productionized systems.