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

Develop consumer-centric web applications, enhance usability, collaborate with designers, implement backend software and APIs, write tested code, and follow agile development cycles.

Build and ship complex consumer-facing full stack applications. Work on React/TypeScript frontends (offline PWAs using IndexedDB/DexieJS and Workbox) and Scala/Play backends with PostgreSQL. Deploy on AWS via Kubernetes. Mentor engineers, collaborate in product-focused cycles, and thrive in a fast-moving startup environment.

The Senior Full Stack Engineer will design, build, and scale healthcare integrations, ensuring high security and quality, while collaborating with cross-functional teams and supporting enterprise-level integrations.

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.

The Senior Full-Stack Engineer will design, implement, and maintain systems for Trading API customers, focusing on both frontend and backend development, while leading projects and mentoring peers.

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.

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, 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.

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.

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.

Lead development and maintenance of Customer.io SDKs across platforms, improve SDK delivery infrastructure (CI, testing, release), partner with product/design, use AI agents to make multi-file code changes, and engage with developer customers to improve experience.

Design, build, and maintain end-to-end, accessible, secure full-stack software for a federal health/civilian agency. Build Section 508-compliant UIs, backend APIs, and services; follow API-first, CI/CD, automated testing, and security best practices; identify and remediate technical debt; mentor engineers and collaborate with cross-functional teams to deliver reliable, performant government software.

Design, build, and maintain scalable serverless and container-based web applications using React, TypeScript, Node.js, and AWS. Implement infrastructure as code with AWS CDK, optimize performance, create automated tests with Playwright, follow CI/CD and DevOps practices, mentor junior engineers, and collaborate in Agile teams to deliver high-quality internal content-creation tools.

Build and evolve APIs and frontend surfaces for data products. Translate business requirements into scalable systems, ensure data integrity, design frontend and backend architecture, improve developer self-serve tooling, collaborate with stakeholders, and mentor engineers while maintaining strong code quality and delivery practices.

Design, develop, and maintain cloud-native full-stack applications (Java/JavaScript) supporting situational awareness and collaboration. Implement microservices in cloud environments, participate in full SDLC, ensure code quality, work in Agile teams, mentor junior developers, and support deployment and system design for mission-critical systems.

Build and productionize LLM-backed agents and workflows: create eval harnesses, observability, provenance and human-review surfaces, extend agent capabilities (web/CMS, OAuth), implement pipeline orchestration, and ship scoring/ranking models and reusable modules to scale across clients.

Build and ship end-to-end features across a TypeScript/Next.js monolith: dashboard, marketing site, billing, email, and AI-assisted tools. Own data models, APIs, third-party integrations, testing, observability, and production quality. Collaborate with the founder, review code, and improve engineering practices while delivering customer-facing features rapidly.

Design, build, and maintain AI-powered B2B SaaS products across frontend, backend, and AI. Own projects end-to-end, collaborate with product and design, ensure maintainability, mentor teammates, and inform roadmap and implementation decisions.

The Senior Fullstack Software Engineer will design, implement, and maintain features for Conveyor's SaaS platform, involving both backend and frontend work, while collaborating closely with team members and mentoring juniors.

Design, build, and optimize scalable cloud and web software with focus on infrastructure, performance, and hardware integration for IoT devices. Collaborate with hardware teams to ensure connectivity and high availability, implement new features, and improve system efficiency.

Build and maintain full-stack product and AI systems: React/React Native frontends, Node.js services, LLM-powered features (agents, RAG), integrations, monitoring, and scalable automation. Ship production features, ensure reliability, and mentor teammates.

Design, build, and own scalable multi-tenant SaaS applications across frontend, backend, and data layers. Improve system architecture, performance, reliability, and testing practices. Integrate AI-assisted tools, mentor engineers, conduct code reviews, and collaborate with Product and Design to deliver intuitive, production-grade software.

Lead and mentor engineers to design, build, and own the Integrations Platform powering 400+ integrations. Drive complex, cross-team projects, set technical direction, develop product functionality and infrastructure using modern frameworks, and enable scalable, declarative integration-building, including AI-enhanced tooling.

Design, build, and maintain scalable backend services and APIs for millions of users. Collaborate with product and UX, implement automated testing, participate in on-call incident management, and mentor teammates while delivering complex distributed-system projects.

Lead end-to-end feature development across API (Node.js), web (React/Next.js), and mobile (React Native). Scope, design, implement, test, and ship production systems; drive architecture and scalability for an AWS-backed, real-time IoT fleet; partner with product and raise engineering standards.