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

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 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 and modernize core Laravel/PHP backend systems and high-performance React/TypeScript frontends. Architect integrations (MLS/RETS/RESO), improve video processing and media delivery, strengthen CI/CD and Docker deployments on AWS/Rackspace, introduce AI-driven automation, and provide senior technical leadership and mentorship.

As a Senior Fullstack Engineer, you'll contribute to backend development for Toast's New Ventures team, collaborating on architecture and launching MVPs while addressing unmet operator needs.

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.

Develop and maintain technology solutions, lead complex projects, consult junior staff, analyze client requirements, and oversee project deliverables for compliance.

Drive feature development and architectural decisions across frontend and backend systems, mentor junior engineers, identify tech debt, and collaborate across departments.

The Senior Full-Stack Developer will design, build, and maintain AIO Logic's cloud-based AXIS platform, utilizing React and Java/Spring Boot to deliver software solutions for complex financial workflows, collaborating with cross-functional teams, and mentoring junior developers.

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.

Join the Entefy team as a Senior Full Stack Engineer to build a scalable full stack application enhancing digital interaction for global clients.

As a Senior Full-Stack and Platform Software Engineer at mabl, you will develop features for an AI-powered test automation platform, enhancing user experiences, designing APIs, and optimizing data pipelines while collaborating with cross-functional teams.

Design, build, and maintain web and mobile applications (React, React Native, NextJS, NodeJS, Python, SQL). Deliver medium-to-large features independently, collaborate with cross-functional teams, conduct code and design reviews, resolve performance and scalability issues, and guide architecture and best practices as the product scales.

The Senior Full Stack Engineer will design and implement APIs with NodeJS, develop UIs with React, manage data pipelines, and deploy projects on AWS.

As a Senior Fullstack Engineer, you'll develop a no-code platform, build UIs and backend services, and improve conversation analysis workflows using AI technologies.

The Senior Fullstack Engineer will lead projects, mentor engineers, and build user-facing SaaS products using React, TypeScript, Node.js, GraphQL, and MongoDB, focusing on team collaboration and effective trade-off decision-making.

As a Senior Full Stack Engineer, you will design and implement systems and tools to support Sales and Customer Success, improving efficiency and user experience while ensuring system reliability and scalability.

As a Senior Full Stack Engineer, you will design and build cloud-native applications, focus on performance and scalability, and ensure platform stability while collaborating with product teams.

Design, develop, and deliver fullstack web solutions, optimize platforms, mentor engineers, and manage product features from ideation to launch.

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, build, and operate end-to-end features across a React frontend and Node.js/TypeScript backend. Implement secure, performant APIs, model and optimize PostgreSQL data, deploy and monitor services on AWS, improve engineering standards through code reviews and testing, troubleshoot production issues, and contribute to scalable system architecture in a distributed team.

Own and implement end-to-end product features across the stack (React/TypeScript front end, Ruby on Rails backend, relational DBs, GCP infra). Design APIs and data models, ensure performance and reliability, integrate AI/LLM-powered features, collaborate with product/design/clinical teams, perform code reviews, and mentor junior engineers.

As a Senior Full Stack Engineer, you will design and implement features, maintain systems, and ensure performance in a fintech environment, collaborating with cross-functional teams.

The Senior Fullstack Engineer will deliver software products, collaborate with product and business teams, lead technical practices, and ensure high-velocity iteration on a mobile advertising platform.

The Senior Full-Stack Engineer will develop claims monitoring tools and backend services, collaborate with other engineers, and influence the product architecture in a health insurance startup.

The Senior Full-Stack Engineer at SafeRide Health will develop and maintain healthcare applications, ensuring high performance and security while collaborating with cross-functional teams in an agile setting.