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.

Owner of end-to-end ecommerce features: design, implement, and maintain scalable backend services and performant React/Next.js frontends. Integrate payment gateways and procurement systems (PunchOut), mentor engineers, uphold code quality, and improve platform stability across Node.js, MySQL, and MongoDB.

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.

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 Full Stack Developer will build end-to-end solutions, collaborate in a remote environment, and write technical documentation. The role requires expertise in Ruby on Rails and various programming paradigms.

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.

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 design and implement APIs with NodeJS, develop UIs with React, manage data pipelines, and deploy projects on AWS.

Senior fullstack engineer to build and scale Brigit's consumer finance platform. Own end-to-end features across frontend (React/React Native/TypeScript) and backend (Java/REST/SQL), optimize database and APIs for high scale, integrate 3rd-party services, implement risk and transaction algorithms, improve CI/CD, testing, monitoring, and internal tooling to support millions of users.

Design and build agent-powered mission consoles, collaborate with stakeholders to improve user workflows, and maintain agentic workflows for mission outcomes.

As a Senior Software Engineer, you will design and build a cutting-edge identity search platform and implement AI systems for defense applications, working closely with cross-functional teams to enhance user workflows and support national security.

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.

Design, develop, test, and maintain full-stack applications using Angular, TypeScript, Node.js/NestJS; build and integrate RESTful APIs; support ETL and data processing with Python/PySpark; collaborate in SAFe Agile with architects, QA, and DevOps; maintain CI/CD, documentation, and federal compliance; mentor developers and help modernize large-scale federal health IT systems.

Responsible for leading a team of engineers, supporting product development, identifying technical issues, and ensuring high-quality code delivery in backend systems at scale.

As a Senior Full Stack Engineer, you'll design and develop custom Shopify applications, integrate solutions, and collaborate with clients to meet their needs.

As an Operations Reliability Engineer, design and implement automations to eliminate manual tasks in brokerage operations, focusing on efficiency and reliability while collaborating with cross-functional teams.

As a Senior Fullstack Developer, you will build and maintain moderation and user-safety applications for Bluesky's Trust & Safety team, collaborating with product teams and improving tools based on user feedback.

As a Senior Full Stack Engineer, you'll build high-performance observability tools, engage with developers, and tackle technical challenges in monitoring applications.

Lead and code fullstack features for the EVV team, provide technical leadership and mentoring, design and execute automated tests, monitor and troubleshoot production, contribute to product technical roadmap, and leverage AI-assisted development tools.

Design, build, and operate cloud-native, high-throughput payment and purchasing systems. Implement reliable backend APIs and modern frontends, embed automated testing and observability, champion event-driven patterns, and own operational readiness and scalability.

This role involves designing and developing scalable web applications, leading projects, mentoring engineers, and ensuring quality through best practices and collaboration.

Design, develop, and maintain web-based UI and REST middleware for federal health IT systems. Participate in Agile/SAFe ceremonies, write design documents, implement features, resolve bugs, and support CI/CD pipelines while collaborating with product, QA, and stakeholders.

As a Senior Full Stack Developer at Capnexus, you'll design and build a cloud-native subcontractor pre-qualification platform using AWS, incorporating AI and modern frontend/backend technologies, ensuring seamless integration and deployment.

Build and own data-driven dashboards and backend services for DeFi risk analysis. Develop React frontends, GraphQL APIs, and cloud-native data pipelines. Collaborate with research and protocol teams, mentor junior engineers, drive architectural improvements to the Alert Portal, ensure code quality through testing and reviews, and identify product and technical enhancements.

Design, build, and maintain scalable web applications using Python and React. Collaborate with teams and ensure application security and performance.