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

Design, build, and secure scalable full‑stack applications integrating enterprise contact‑center platforms (IVR, call routing, real‑time logging) and Salesforce. Collaborate in Agile teams, implement RESTful APIs, cloud‑native and containerized architectures, apply DevSecOps and TDD practices, and ensure secure, testable, high‑quality software.

Full Stack/Frontend Developer to build responsive, accessible, performant UIs using React or Vue, integrate with Java/Spring backends, implement component-based architectures, consume REST APIs, write frontend tests, use modern tooling (Webpack/Vite/Babel/ESLint), and work in Agile teams.

Design, develop, and maintain backend microservices in Java/Spring Boot; build RESTful APIs; implement Angular front-end; integrate with Kafka and AWS S3; collaborate across the SDLC; troubleshoot and debug full-stack issues. Fraud prevention experience required.

Design, develop, and maintain scalable Java/Spring Boot backend and Angular frontend applications. Build microservices, RESTful APIs, event-driven solutions with Kafka, implement fault tolerance (Hystrix/circuit breakers), observability (SLI/SLO), and deploy on Kubernetes/AWS. Collaborate with cross-functional teams, mentor junior developers, and ensure reliability and performance.

Lead consolidation and modernization of two legacy giving marketplace applications into a single scalable stack. Design and build backend services with Java, Spring Boot, and Hibernate JPA; develop responsive Angular front-end using NgRx and SCSS. Refactor legacy code, improve performance and scalability, implement features, ensure UI/UX feasibility, and perform code reviews.

Develop and maintain web applications using Java/Spring Boot backend and Angular frontend. Build microservices and RESTful APIs, integrate frontend with backend, work with Kafka and AWS S3 as needed, and collaborate across the SDLC to troubleshoot and deliver user-focused solutions.

Design and build backend microservices with Java and Spring Boot, create and maintain RESTful APIs, and develop Angular frontend components. Work across the full stack, integrate asynchronous patterns (Kafka) and AWS S3, collaborate with cross-functional teams, and troubleshoot/debug applications throughout the software lifecycle.

Develop and maintain web applications across the full stack using Java/Spring Boot backend and Angular frontend. Build microservices, design RESTful APIs, integrate frontend components, work with Kafka and AWS S3 as needed, and collaborate with cross-functional teams to troubleshoot and deliver solutions throughout the SDLC.

Design, develop, and maintain full-stack web applications using Java/Spring Boot backends and Angular frontends. Build RESTful APIs and microservices, implement fault tolerance (Hystrix/circuit breakers), event-driven solutions with Kafka, and observability (SLI/SLO). Deploy and manage services on Kubernetes and AWS, collaborate with cross-functional teams, mentor junior developers, and ensure system reliability and performance.

Design, build, and modernize cloud-native applications on Azure (AKS, App Services, Functions). Maintain and enhance legacy React/.NET applications, develop REST APIs, monitor performance, and migrate .NET apps to microservices. Act as subject-matter expert in asset management, communicate with stakeholders, and support full-stack development across frontend and backend technologies.

Build and maintain polyglot full-stack applications, architect scalable microservices, implement agentic AI/LLM workflows, develop modern frontends, manage AWS cloud infrastructure, and own the full software lifecycle including deployment and production monitoring.

Design, develop, and maintain backend microservices in Java/Spring Boot; create RESTful APIs; build Angular frontend components; integrate asynchronous communication (Kafka) and AWS S3 storage; collaborate across the SDLC and troubleshoot full-stack issues.

Design, develop, and maintain high-performance web applications and WebAPIs using .NET 6 and React. Build scalable, reliable services, optimize performance, troubleshoot defects, and collaborate with product and development teams. Use Azure platform services, NoSQL/SQL databases, CI/CD pipelines, and propose continuous improvements.

Build end-to-end product features to improve teacher activation, engagement, and monetization. Optimize onboarding and early user experiences, design scalable AI-powered and growth systems, run experiments with product/design/data, iterate using data and user insights, maintain high-quality codebase, and mentor other engineers.

Design, build, and operate scalable full-stack systems for an AI-native enterprise platform: backend services, APIs, frontend React apps, workflow orchestration, integrations, testing, CI/CD, monitoring, and production readiness while collaborating with product and customers.

Lead the engineering effort for a seed-stage dating app: audit and improve the existing codebase, design and build v2 (mobile and backend), implement real-time features, define engineering standards, scale infrastructure on AWS, and, after fundraising, hire and mentor a small team while shaping the technical roadmap.

Lead architecture and hands-on development of cloud-native Java microservices with an Angular frontend. Build FHIR/HL7-based interoperability pipelines, design scalable event-driven systems on GCP, and ensure data integrity across PostgreSQL/Spanner while defining engineering best practices and guiding agile teams.

Lead architecture, modernization, and development of Group Insurance applications. Modernize mainframe monoliths into Java microservices and micro-frontends on cloud, mentor distributed Agile teams, collaborate with enterprise architecture, product owners and infrastructure, and enable test automation and integrations. Approximately 10% domestic travel.

Develop, maintain and evolve a high-scale US sports trading platform. Build React/TypeScript frontends, backend microservices, optimize SQL and performance, implement CI/CD and automated testing, mentor junior engineers, and collaborate with stakeholders and architecture teams to ensure resilience and integration.

Lead frontend-leaning full-stack implementation work for carrier and enterprise integrations: architect reusable UI and API layers, author RFCs, guide technical delivery, enforce testing and security best practices, and partner with cross-functional teams to scope and ship production integrations.

The Fullstack Engineer will design, develop, and improve software for public safety agencies, adhering to quality, security, and architecture standards while collaborating with teams.

Develop and maintain front-end and back-end components of AI-driven products, collaborating with teams to enhance user experience and build proof of concept products.

The Full-Stack Engineer will enhance backend functionality, collaborate with teams, and maintain platform performance and security, requiring expertise in Python.

The Full Stack Engineer will design and build features for LaunchDarkly's Observability product, focusing on Infrastructure-as-Code and enterprise integrations, while participating in architecture discussions and maintaining high engineering standards.

As a Mid-Level Full Stack Developer, the role involves building and maintaining web applications, implementing new features, and optimizing performance using Ruby on Rails in a remote setting.