Top Senior Software Engineer Jobs in Denver & Boulder, CO

Build and ship backend features end-to-end using Ruby on Rails and SQL. Lead complex technical projects, solve architecture challenges, establish standards, conduct meaningful code reviews, resolve high-risk bugs, document systems, collaborate across engineering teams, and mentor junior engineers.

Designs and develops scalable, concurrent software for HPE’s Alletra enterprise storage platform using modern C++ and Linux. Responsibilities include building distributed storage features, debugging performance and reliability issues, creating automated tests, participating in architecture and code reviews, integrating technologies, and mentoring engineers. The role requires expertise in systems infrastructure, multithreaded programming, algorithms, data structures, and software architecture.

Develops and maintains software requirements, architectures, algorithms, APIs, backend services, and user interfaces for SATCOM mission-planning systems. Supports Agile and DevSecOps development across design, integration, testing, and deployment, including CI/CD automation, vulnerability scanning, code reviews, and performance optimization. The role works with space and ground systems, geospatial visualization, databases, Kubernetes, and modern front-end technologies. It requires active Secret clearance, U.S. citizenship, full-time onsite work in Colorado Springs, and up to 10% travel.

Develops, integrates, tests, maintains, and supports Java-based software systems and mathematical algorithms for Boeing’s C2BMC missile defense applications. Responsibilities include software architecture, requirements decomposition, interface development, design documentation, coding, debugging, performance optimization, agile execution, integration and testing, operational support, and technical issue resolution. The role collaborates with systems engineering, integration and test teams, and industry partners while supporting full software lifecycle activities for ballistic missile defense systems.

Designs, develops, integrates, and certifies a company-wide digital test procedure application. Responsibilities include full-stack software development, requirements analysis, architecture support, implementation, testing, cross-functional collaboration, Agile development, process improvement, and enterprise application maintenance. The role works on-site at least three days per week and may involve travel between company locations.

Develop and test Java-based C2BMC missile defense applications across the full software development lifecycle. Responsibilities include architecture and requirements development, design artifacts, coding, reviews, integration and testing, agile execution, issue resolution, and performance optimization. The role also involves collaborating with industry partners, documenting test activities, deploying integration processes, and mentoring junior engineers. Work is fully onsite in Colorado Springs or Huntsville and requires an active U.S. Secret clearance.

Build and scale mission-critical tips, earnings, and payroll platforms for restaurant employees. Own systems end to end, lead complex projects from design through deployment, improve reliability and correctness, collaborate with product and design, review code, mentor engineers, and deliver scalable backend services that affect employee pay and product revenue.

Build and architect Clear Street Active, a high-performance trading platform for active traders. Develop responsive web interfaces integrating real-time market data, low-latency execution workflows, and advanced trading tools. Collaborate with cross-functional teams on large-scale initiatives while emphasizing scalability, performance, API quality, maintainability, and developer experience.

Architect and build a high-performance trading platform for active traders. Develop responsive web interfaces integrating real-time market data, low-latency execution workflows, and advanced trading tools. Collaborate with cross-functional engineering teams on large-scale initiatives, emphasizing scalability, performance, API quality, maintainability, developer experience, and end-user usability.

Design, build, and operate enterprise applications, APIs, integrations, and distributed event-driven systems using C#/.NET, React, cloud platforms, and messaging technologies. Integrate business systems, implement resilient architectural patterns, add AI capabilities, and support CI/CD, observability, security, and production troubleshooting. Collaborate with stakeholders and engineers, contribute to technical standards, lead projects when needed, and deliver reliable solutions across engineering, manufacturing, supply chain, and finance functions.

Leads delivery of complex software features for desktop utility design tools, translating ambiguous requirements into technical plans and managing performance, correctness, and reliability. Establishes architecture, coding standards, CI/CD and AI-assisted development practices; mentors engineers and leads design and code reviews. Partners with product, QA, delivery, and customers to create reusable solutions, contribute to roadmaps, and represent the team in architecture discussions.

Build and scale full-stack benefits renewal products using Ruby on Rails and JavaScript/React. Design frontend experiences, backend APIs, automated workflows, and tests; own features from specification through launch and iteration. Lead complex, multi-quarter initiatives, collaborate cross-functionally, conduct experimentation, mentor engineers, and apply AI tools to accelerate development and improve testing. The role focuses on reducing errors and simplifying health insurance renewal processes for customers.

Lead development, maintenance, and optimization of high-volume billing platforms supporting revenue operations. Architect AI and machine learning solutions to automate billing workflows, prototype scalable capabilities with product and engineering partners, and eliminate operational bottlenecks through automation and deployment pipelines. Establish engineering standards, conduct architectural reviews, and build observable, secure, PCI-compliant microservices and distributed systems.

Build Apollo’s AI-powered Builder Studio end to end, including chat-driven app creation, live previews, generated-app runtimes, workflows, integrations, delegated permissions, security, and reliability. The role requires strong full-stack development, production LLM experience, frontend expertise with complex UIs, backend and workflow design, and ownership of an ambiguous 0-to-1 product.

Build and maintain authentication and fine-grained authorization systems using Auth0 and OpenFGA. Own OAuth 2.0 and OpenID Connect implementations, identity federation, token flows, and permissions for AI agents. Lead cross-team technical projects, set engineering standards, review code, and mentor engineers. The role requires strong backend development skills and experience with identity providers, ReBAC systems, and complex multi-tenant authorization models.

Develop and scale backend Java and Kotlin software powering patch discovery, packaging, and deployment across millions of endpoints. Design scalable systems, APIs, data structures, caching solutions, and relational databases while maintaining high testing and code-quality standards. Collaborate with AI workflow, server, platform, design, and product teams. Occasional React or Angular work may support patching workflows and dashboards.

Designs and evolves AWS infrastructure as code using CDK, develops backend software primarily in TypeScript, and applies secure engineering practices for regulated environments. The role contributes to architecture, code reviews, CI/CD pipelines, production support, observability, and on-call operations. It collaborates cross-functionally, builds scalable and reusable systems, supports SOC 2 compliance, and uses AI coding assistants to improve development, testing, and documentation.

Develop and maintain C#/.NET software for electric and gas distribution engineering tools. Implement features, fixes, integrations, tests, and CI/CD automation while configuring enterprise systems for customer needs. Collaborate in Scrum, participate in reviews, reduce technical debt, document processes, and mentor teammates. The role may involve GIS or Enterprise Asset Management integrations and requires strong software development experience in utility or energy infrastructure environments.

Lead organization-wide technical initiatives for Gusto’s API and AI agent platform. Design reliable, scalable API contracts and agent-facing tools, write clean Ruby on Rails code, mentor engineers, improve reliability and observability, engage developer customers, and troubleshoot production issues.

Build and scale full-stack software for employer and Employee Assistance Program products, including employer portals, patient and provider workflows, eligibility, authorization, and billing. Lead technical projects, design secure distributed systems, mentor engineers, contribute to engineering culture, and use modern technologies and AI-assisted development tools. Collaborate cross-functionally to expand access to mental healthcare.

Build and ship web-based transportation management software for trucking customers. Collaborate with product, UX, and engineering teammates to understand user workflows, solve domain problems, deliver features rapidly, and maintain an effective balance between quality and velocity. The role requires proactive ownership, strong communication, frequent collaboration, and willingness to learn the trucking industry and engage with customers.

Lead backend engineering for a high-performance, data-intensive SaaS platform. Responsibilities include defining technical vision, designing scalable and highly available systems, executing technical projects, participating in architecture decisions, monitoring and optimizing services, improving CI/CD and infrastructure, conducting postmortems, mentoring engineers, documenting practices, and aligning with partner teams.

Leads architecture and hands-on development of scalable backend systems and APIs supporting real-time applications. Owns the engineering lifecycle, writes high-performance code, establishes testing and reliability practices, resolves production issues, guides technical roadmaps, collaborates cross-functionally, and mentors engineers. The role requires expertise in object-oriented backend development, distributed cloud systems, automated testing, system monitoring, and technical leadership.

Design and deliver Android system applications for Toast POS devices, including device policy enforcement, setup, firmware and app updates, background services, and fleet deployment. Lead technical design, cross-functional planning, Android and hardware upgrades, automated testing, production issue investigations, and staged rollouts. Mentor engineers and collaborate with product, hardware, QA, and software teams to build secure, reliable device-management systems.

Build and maintain high-performance, resilient SDKs across multiple programming languages and platforms. Develop features, improve reliability, collaborate with engineering and product teams, maintain open-source repositories, and influence technical and product decisions. The role requires strong software engineering fundamentals, polyglot development ability, library-building experience, production-quality coding, and expertise in unit, integration, load testing, and benchmarking.