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

Develop fullstack web applications, enhance platform performance, collaborate on high-impact opportunities, and ensure stable, scalable solutions. Engage in rapid iterations and be a committed team player.

Develop and deploy customer-focused web, mobile, and backend applications across the full software stack. Design major features, contribute to architecture decisions, conduct code reviews, and ensure secure, high-quality implementations. Collaborate with stakeholders and cross-functional teams using Agile and SDLC practices. Manage version control, CI/CD, environments, and releases; maintain automated test coverage and perform root-cause analysis. Build and optimize relational data solutions using SQL Server, including complex queries, stored procedures, and performance tuning.

Leads technical vision and strategy for Affirm’s Marketplace, Search, Ads Platform, and consumer experiences. Designs scalable full-stack platforms, guides architecture and technical excellence, coordinates initiatives across engineering teams, mentors engineers, and drives reliable delivery of customer-focused products across iOS, Android, and Web.

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.

Own fullstack development for Broad Arrow Auctions across customer-facing auction experiences and internal live-auction tools. Build scalable web applications, APIs, integrations, automated tests, and cloud infrastructure using Azure and AWS. Maintain Billboard auction software, integrate Microsoft Dynamics 365, monitor production systems, participate in on-call support, contribute to architecture, improve reliability and performance, and mentor less experienced engineers.

Own end-to-end full-stack feature development across React/TypeScript interfaces and Elixir backend services for spacecraft modeling, simulation, and ground-control software. Drive architecture, technical debt reduction, performance, reliability, testing, API design, and production deployment. Mentor engineers, establish coding standards, collaborate with product, design, QA, operators, and astrodynamics teams, and deliver complex data-dense, real-time applications.

Build and scale full-stack applications, backend services, APIs, infrastructure, and user experiences supporting millions of users. Design reliable, high-performance systems; partner with Product, Design, and Data; own projects through deployment and optimization; improve observability and developer productivity; and support AI adoption through automation and AI-powered workflows.

Lead full-stack software development from design through delivery for Judi Health’s healthcare benefits platform. Partner with product, design, and QA teams to define requirements, build scalable features, provide technical leadership and support, and expand the platform using Python, AWS, React, TypeScript, and PostgreSQL in an Agile/Scrum environment.

Build and evolve scalable full-stack products using React, TypeScript, Next.js, Python, and Django. Own frontend and backend architecture, APIs, testing, CI/CD, observability, performance, and reliability. Collaborate with Product and Design, lead technical initiatives, identify risks, define solutions in ambiguous environments, and mentor engineers. Develop 0-to-1 experiences and production systems across cloud-based environments while establishing engineering standards and monitoring technical and product metrics.

Build and maintain full-stack features for Vanta’s third-party risk management products, including vendor onboarding, lifecycle management, monitoring workflows, data models, and platform abstractions. Write tested code, participate in reviews and architecture decisions, and collaborate with product, design, and engineering teams to deliver customer-facing functionality. Experience with TypeScript, React or Node.js, web applications, databases, and REST or GraphQL APIs is expected.

Lead development of secure, scalable digital banking software across front-end and backend systems. Design Angular or React applications, build APIs, optimize SQL performance, integrate third-party platforms, improve code quality, implement testing strategies, and mentor engineers. Collaborate with cross-functional teams in an Agile environment while supporting cloud-native practices, regulatory compliance, and continuous product improvement.

Develop and maintain full-stack features for CMS’s Unified Case Management system. Responsibilities include building Java and Spring Boot backend services, APIs, data models, Angular or React interfaces, database interactions, and automated tests using test-driven development. The engineer will optimize performance, scalability, security, and data integrity; collaborate on system design and integration; reduce technical debt; and support teammates in a remote-first environment.

Designs, builds, and scales full-stack web applications using React, TypeScript, Python, and AWS. Develops APIs and backend services, optimizes relational and document databases, implements automated testing, and manages Docker-based deployments and CI/CD pipelines. Collaborates with technical and non-technical stakeholders, translates business requirements into production-ready solutions, communicates clearly, and mentors colleagues while promoting strong engineering practices.

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 ship full-stack features, including REST APIs, single-page applications, data models, cloud-based containerized services, and relational database solutions. Translate product requests into deliverable work, contribute to architectural decisions, review pull requests, and protect patient data by maintaining strict PHI-handling practices. Work in a trunk-based development environment with short-lived branches, frequent releases, and continuous collaboration.

Build and own a multi-tenant web platform for managing AI infrastructure. Develop Next.js and React features, server-side authentication and API proxying, generated TypeScript SDKs, resilient data synchronization, design-system components, accessibility, performance, testing, observability, and production deployment. Collaborate with backend and globally distributed teams, review code, troubleshoot production issues, and mentor junior engineers.

Design, implement, and maintain scalable serverless backend services and responsive Next.js front-end components. Build data scrapers and integrations, improve CI/CD and IaC, mentor junior engineers, and collaborate with product and clients to solve complex compliance problems.

Senior Full Stack Engineer building scalable, high-performance web applications. Own feature design through delivery, write clean reusable code, optimize databases, work with CI/CD, containers, cloud, distributed systems, mentor teammates, and maintain zero customer-reported bugs.

Build and maintain full-stack software for startup clients, including backend services, frontend experiences, new features, redesigns, bug fixes, and product improvements. Collaborate daily with product managers, designers, and engineers in a distributed, agile environment. Take ownership across the technology stack, write clean maintainable code, contribute to client missions, and support team growth and knowledge sharing.

Develop and optimize high-scale Adobe Commerce ecommerce platforms using PHP, JavaScript, Node.js, GraphQL, REST, and MySQL. Separate business logic from presentation layers, improve database and caching performance, build CI/CD validation, monitor production systems with New Relic, and create endurance load tests. Integrate identity, payment, and tax systems while mentoring junior engineers and leading offshore teams.

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 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.

Designs, builds, tests, deploys, and optimizes full-stack product features using React and Python. Develops GraphQL integrations, scalable backend services, data visualizations, analytics instrumentation, and production-ready platform capabilities. Contributes to UX workflows, CI/CD, monitoring, code quality, and stakeholder updates while collaborating in agile sprints and evaluating new technologies.

Build and modernize full-stack software for space mission systems, including distributed microservices, cloud-native applications, DevSecOps pipelines, automated testing, and mission operator interfaces. Integrate and test ground and flight software through simulation, emulation, and interface validation. Collaborate with space systems and operations teams, provide technical leadership, mentor engineers, and support DoD and intelligence-community programs.

Lead technical direction and delivery for the Acquisition & Onboarding full‑stack team. Build and maintain mobile (React Native/native) and web experiences, backend services at scale, and operational tooling. Drive architecture, mentor engineers, ensure reliability/monitoring/on‑call readiness, collaborate with product and design, and improve dev processes, testing, and release practices to impact conversion and retention.