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

The Senior Full-Stack Engineer will manage client relationships, design integration solutions, and ensure seamless delivery and optimization of technical workflows, while leveraging AI for efficiency.

Lead design and build of an AI-native marketing platform: integrations, multi-agent orchestration, UIs, tooling, analytics, CI/CD, auth/multi-tenancy, and production AI agents to automate marketing workflows and drive adoption across teams.

The Senior Full Stack Engineer develops and maintains the US Sports platform, coaches junior engineers, collaborates with stakeholders, and ensures high system performance under demand.

The Senior Fullstack Engineer will build and manage enterprise authentication systems, improve user session management, ensure security compliance, and support internal API usage across services, while enhancing performance and reliability.

Lead design and implementation of the PSA Liquidity Platform connecting buyers and sellers. Build buyer tooling, matching/ranking engines, and seller experiences. Architect and operate microservices and Kafka-driven systems on Kubernetes/AWS, instrument observability, apply AI tooling across the SDLC, and drive cross-functional delivery from 0-to-1 while owning end-to-end outcomes.

Build end-to-end features, design intuitive interfaces, manage asynchronous backend jobs, and contribute to open-source efforts, while leading project development from concept to monitoring.

As a Full Stack Engineer at Deepnote, you'll develop and enhance features across the tech stack, support community engagement, and tackle complex engineering challenges.

Lead the development of Coperniq's platform by designing, developing, and maintaining scalable full-stack solutions while collaborating with teams and mentoring juniors.

Design, scope, and implement scalable full‑stack ecommerce solutions. Improve platform performance and usability, collaborate with Product and Design, run experiments, ship features, and ensure seamless integration across the product ecosystem.

The Senior Software Engineer will design, develop, and optimize scalable PHP APIs and web applications, collaborating with product and design teams to support product development and implement best coding practices.

Build and maintain scalable full-stack features for a fintech SaaS platform. Implement React front-ends and Node.js/NestJS back-end APIs, troubleshoot production systems (databases, queues, caches, microservices), write tests and clean code, collaborate with product and design, participate in code reviews, and prioritize technical debt while scaling the user base.

Design, develop, and maintain full-stack web applications using Java/Spring Boot backends and Angular frontends. Build RESTful APIs, write clean code, collaborate with cross-functional teams, troubleshoot issues, and participate across the SDLC.

Design, develop, and maintain web applications and RESTful APIs using Java/Spring Boot. Develop and maintain PL/SQL stored procedures and Oracle database logic. Participate across the SDLC, troubleshoot backend and database issues, collaborate with cross-functional teams, and improve development processes and tooling.

Lead consolidation and modernization of two legacy giving marketplace applications into a single scalable stack. Re-architect, refactor, and optimize back end (Java, Spring Boot, Hibernate) and front end (Angular, NgRx, SCSS). Implement features, ensure UI/UX feasibility, address performance and scalability, conduct code reviews, and collaborate with the team to deliver a robust application.

Design, develop, and maintain web applications using Java/Spring Boot backends and Angular frontends. Build RESTful APIs, write clean maintainable code, participate across the SDLC, collaborate with cross-functional teams, troubleshoot full-stack issues, and help improve development processes and tools.

Lead full‑stack development of enterprise web and middle‑tier applications for financial advisors using Angular/TypeScript and Java/Spring. Design, implement, test, and deploy features in an Agile Scrum team, driving CI/CD, cloud (AWS) deployments with Docker, Kubernetes, and Terraform, while mentoring engineers and collaborating with business stakeholders.

Design, build, and maintain backend applications, microservices, and APIs; implement third-party integrations; ensure security, testing, and documentation; deliver client-facing features; collaborate with product and business stakeholders; estimate scope/timelines; work across the stack to create scalable, high-performance systems.

Build and operate end-to-end backend services and web frontends for a centralized mission operations platform. Design APIs and integrations, implement performant accessible UIs, partner with cross-functional stakeholders to translate mission and business processes into reliable software, and own features from design through production while reducing operational complexity.

Own and ship end-to-end full-stack features for a high-scale, AI-native publishing marketplace. Design APIs, optimize queries, deploy cloud-native apps, build LLM-powered capabilities, ensure security and privacy compliance, mentor engineers, influence architecture, and maintain reliability and performance under load.

Build and operate end-to-end premium purchasing and subscription systems (Stripe, Apple/Google IAP, payments). Own projects from design through rollout and reliability, instrument observability, debug production, define metrics, mentor engineers, and drive technical direction and standards.

Build end-to-end full‑stack features for AI agents, spanning UI (React/TypeScript), backend services (Elixir/Go/Python), APIs, and integrations. Drive architecture, code quality, CI/CD, testing, observability, feature-flagged delivery and A/B experiments. Partner with product/design, mentor junior engineers, and apply emerging AI models and tools to improve agent reasoning, actions, and business impact.

The Sr. Full Stack Developer will design and build full-stack applications, focusing on AI-powered solutions, and lead code reviews while mentoring junior engineers in the Advanced Technology Center.

As a Senior Software Engineer in ZT1, you will lead backend system development, manage projects, and influence product direction in a fast-paced, AI-centric environment.

As a Full Stack Engineer III at Calendly, you'll develop features, scale the platform, and mentor team members while using various technologies.

As a Senior Full-Stack Engineer, you will build features across React/TypeScript and Python/Django, shape product outcomes, and collaborate with cross-functional teams to ensure user satisfaction and engineering quality.