Top Senior Software Engineer Jobs in Denver & Boulder, CO

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.

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.

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.

Design, build, deploy, and support scalable Java microservices on AWS. Provide technical leadership, architectural direction, code reviews, troubleshooting, proof-of-concept development, and cross-functional collaboration. Work with high-throughput data, messaging systems, distributed architectures, observability, and AI-assisted development tools. Participate in on-call support, mentor engineers, lead architectural initiatives, and deliver reliable SaaS platform features.

Develop and support software for satellite radiometric calibration, imaging sensor commissioning, and space operations. Responsibilities include service architecture, reliability monitoring, CI/CD integration, automated testing, operational troubleshooting, cloud-based distributed systems design, and collaboration with scientists and software teams. The role supports production and test environments, investigates data anomalies, and advances calibration operations for satellite imagery and geospatial data products.

Own the development and maintenance of large-scale React Native applications for iOS and Android. Lead architecture improvements, React Native upgrades, native module development, performance optimization, automated testing, CI/CD reliability, and production debugging. Collaborate with cross-functional product pods, contribute to technical discovery and architecture, mentor engineers, and raise engineering standards while delivering scalable, maintainable mobile experiences.

Build and scale low-latency ad-serving software handling billions of daily auctions. Responsibilities include developing data- and model-driven features, optimizing algorithms and architectures, reducing cloud costs, extending observability, supporting distributed infrastructure, participating in on-call rotations, and documenting systems and incident procedures.

Design, build, and operate foundational developer infrastructure across CI, build systems, deployment orchestration, and test platforms. Improve build speed, deployment safety, and test reliability while owning services end to end, including SLOs, observability, and on-call responsibilities. Partner with engineering teams to address platform pain points and lead cross-cutting technical projects through production.

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 own backend services and APIs supporting retirement money movement, payments, settlements, reconciliation, compliance integrations, payroll, and financial workflows. The role involves shipping reliable production code, debugging incidents, improving observability, partnering with product, compliance, and operations, and mentoring engineers. Candidates should have extensive software engineering experience, financial systems expertise, end-to-end ownership, and Ruby on Rails or comparable backend framework experience.

Lead technical strategy and execution for foundational Trust and Safety systems supporting consumer risk and credit reporting. Design and operate highly available backend systems, improve reliability and monitoring, establish engineering standards, guide complex cross-functional initiatives, and mentor engineers. The role involves ownership of system architecture, technical planning, operational readiness, code quality, and team development.

Develop scalable C++ software that defines and enforces endpoint behavior across millions of managed Windows endpoints. Responsibilities include implementing features, improving platform performance, shipping production code, designing new systems, writing architecture documents, defining subsystem contracts, and collaborating with server, UI, product, and design teams. The role requires deep Windows systems and kernel-driver expertise, with preferred experience in WHQL, minifilter or WFP drivers, macOS Endpoint Security, and Linux kernel development.

Lead the design, development, and delivery of scalable payroll onboarding software. Drive technically complex initiatives, influence architecture and roadmaps, collaborate across product, design, and engineering, improve reliability, promote coding best practices, mentor engineers, and use AI tools to enhance development productivity.

Build and ship production software for Toast’s retail platform, partnering with engineering, product, and customers. Responsibilities include identifying opportunities, designing and prototyping end-to-end solutions, making foundational technical decisions, incorporating customer feedback, tracking industry trends, and deploying AI-powered experiences. The role supports large grocery and convenience-store customers and may involve visiting stores to understand operator workflows.

Build and scale the PSA Liquidity Platform connecting buyers and sellers across PSA Partner Offers and eBay Consignment. Responsibilities include developing buyer tooling, pricing and ranking engines, seller experiences, microservices, distributed event-driven systems, and observability. The role owns end-to-end product delivery, cross-functional execution, technical architecture, ecosystem integrations, and production outcomes while using AI throughout the software development lifecycle.

Develop and maintain scalable Java and Spring Boot REST services, APIs, and microservices for mission-critical geospatial systems. Support containerization, orchestration, CI/CD, DevOps automation, testing, infrastructure deployment, data platforms, and third-party integrations. Contribute to architecture, performance optimization, troubleshooting, documentation, stakeholder demos, and Agile delivery. The role requires onsite work in Herndon, Virginia and collaboration on national security missions.

Build and own full-stack services and APIs enabling businesses to offer and manage 401(k) plans. Design scalable features, evolve system architecture, establish engineering best practices, collaborate with product, design, compliance, and operations, debug production issues, and improve reliability, observability, and operational tooling. The role requires end-to-end system ownership, production support, and cross-team technical influence.

Build and maintain MongoDB’s distributed database infrastructure for cluster scalability. Design data partitioning, data movement, dynamic scaling, workload execution, and resilient distributed protocols. Solve complex performance and low-latency systems problems, contribute production-quality C++ code, participate in design and code reviews, lead new feature development, and mentor engineers.

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.

Design and implement scalable, secure, high-performance software systems and public-facing APIs. Lead system design, apply agentic coding workflows, collaborate with Product and Data Science, mentor engineers, and own initiatives improving efficiency, performance, and customer satisfaction. The role requires extensive experience with highly available distributed systems, API versioning and rate limiting, modern backend and frontend technologies, AWS, and Domain-Driven Design.

Design, build, and own backend services, APIs, and integrations supporting customer care workflows. The role connects Salesforce, billing, identity verification, document management, and iPaaS platforms; requires automated testing, code reviews, incident response, performance monitoring, and cross-functional collaboration. The engineer will also apply AI tools and may build production LLM solutions.

Designs, builds, and ships scalable full-stack features for Toast’s restaurant and retail technology platform. Responsibilities include developing resilient backend services and APIs, responsive web interfaces, distributed systems, and high-throughput enterprise solutions using Java, Kotlin, React, and TypeScript. The role requires solving ambiguous technical problems, ensuring system reliability and observability, applying engineering best practices, collaborating cross-functionally, and mentoring engineers.

Lead a small team developing and supporting a business-critical verification platform. Design and deliver scalable, maintainable, performant systems during a ground-up re-architecture using Golang, React, cloud platforms, Kafka, SQL, .NET, and TypeScript. Provide technical leadership, solution governance, estimation, hands-on development, escalation support, code-quality oversight, and coaching while collaborating with UK teams and ensuring reliable delivery.

Build and maintain production frontend applications for mission-critical communications software. Develop reusable UI components, integrate frontend systems with APIs and backend services, implement testing and CI/CD pipelines, resolve defects and performance issues, and support technical documentation. Translate requirements into development tasks, contribute to agile planning, provide technical leadership and mentorship, and collaborate with engineering, UI/UX, and customer stakeholders.

Leads software systems engineering for SATCOM mission planning supporting military NC3 networks. Responsibilities include requirements, architecture, API and backend development, user interface implementation, integration, testing, deployment, code reviews, security, performance improvements, mentoring, and Agile DevSecOps delivery. The role requires onsite work in Colorado Springs, active U.S. Secret clearance, U.S. Person status, and up to 10% travel.