Top Principal Software Engineer Jobs in Denver & Boulder, CO

Lead design, development, and delivery of mission-critical SIEM platform features. Define technical vision, own quality and uptime, mentor engineers, collaborate cross-functionally, build AI-assisted workflows, and drive performance, monitoring, and architecture decisions.

This role involves leading technical projects across multiple teams, designing scalable systems, collaborating with cross-functional teams, and mentoring engineers, focusing on payroll and tax systems at Gusto.

Lead design and build of scalable backend systems and data platforms; own architecture and production deployments; improve reliability, performance, and observability; mentor engineers and collaborate with Product, Data Science, SRE, and Security.

Lead architecture and implementation of a scalable data lakehouse and streaming platform. Define technical strategy, build resilient systems, optimize performance, mentor engineers, and partner across teams to enable analytics and ML use cases using modern data platform technologies.

Lead design and implementation of scalable, cloud-native (AWS) data platforms and pipelines. Mentor teams, drive technical decisions and enterprise architecture, ensure security and high availability, work cross-functionally with customers and product teams, and support/maintain production systems and APIs.

Lead and mentor an engineering team building GovIntel and GovChannel product capabilities. Own technical direction, design and deliver scalable SaaS features, APIs, integrations, and platform reliability. Partner with Product, QA, Cloud Ops, and stakeholders to prioritize work, drive CI/CD and observability practices, lead reviews and incident response, and apply AI-assisted tools to improve development speed and quality.

Lead long-term technical strategy and execution across multiple teams, architecting and evolving foundational frontend/backend systems and platforms at massive scale. Drive AI/ML adoption, solve ambiguous, high-impact problems, remain hands-on in critical system design and implementation, and align senior leaders on roadmaps and engineering standards.

Design and develop software applications for space systems, providing technical leadership and mentoring while ensuring high availability and security practices.

Lead frontend architecture and implementation for a high-performance SPA and Node.js BFF. Solve algorithmic, concurrency, and memory challenges, optimize performance and builds, drive observability, security, and CI/CD, mentor engineers, and collaborate with product, UX, and SRE teams to deliver resilient, distributed real-time collaborative features.

The Principal Software Engineer designs, develops, and tests software for space systems. Responsibilities include coding, technical leadership, system architecture, and mentoring, while adhering to best practices and software development methodologies.

Lead technical architect and hands-on principal engineer for the SOC Experience team, building scalable investigation workflows, agentic LLM features, automation, remediation actions, and analyst tooling. Drive architecture, mentor engineers, prototype solutions, ensure reliability and observability, and partner with product, UX, and SOC stakeholders to turn operational problems into auditable, production-grade systems.

Lead architecture, modernization, and development of Group Insurance applications. Modernize mainframe monoliths into Java microservices and micro-frontends on cloud, mentor distributed Agile teams, collaborate with enterprise architecture, product owners and infrastructure, and enable test automation and integrations. Approximately 10% domestic travel.

Design and develop flight software for space systems, mentor engineers, and ensure adherence to software development principles in an Agile environment.

Develop and maintain embedded satellite command-and-control, mission planning, and data analysis software. Perform full software lifecycle tasks (requirements, architecture, design, code, test, integration, documentation). Build and support test infrastructure, CI/CD and containerized deployments. Work onsite regularly and collaborate across engineering and program teams. Requires active TS/SCI clearance and experience with modern cloud, embedded, and software engineering practices.

Designs and implements embedded satellite command-and-control, mission planning, and data analysis software. Performs full software lifecycle activities (requirements, architecture, design, coding, testing, integration, documentation, support) and maintains on-site engagement. Works across programs using CI/CD, containerization, cloud, and modern web/back-end/front-end technologies.

Develop, test, and maintain embedded software for satellite, airborne, and ground systems. Perform full software lifecycle activities (requirements, architecture, design, code, test, integration, documentation). Support test infrastructure, CI/CD, containerized deployments, and collaborate across engineering teams while working on-site.

Design, develop, test, and maintain embedded satellite command & control, mission planning, and data analysis software. Perform full software lifecycle work (requirements, architecture, code, integration, test, documentation), collaborate across teams, and support on-site development and deployment activities.

Design, implement, test, and maintain embedded software for satellite, airborne, or ground systems. Perform full software life-cycle tasks (requirements, architecture, coding, integration, testing, documentation) and collaborate across teams; maintain on-site schedule and support program deliverables.

Design, implement, test, and integrate embedded software for satellite/airborne/ground systems. Perform full software lifecycle tasks (requirements, architecture, coding, testing, integration, documentation) and support deployments and operations on Linux. Collaborate across teams, maintain formal development practices, and work on-site regularly.

Build and maintain a TypeScript/JavaScript SDK for IP video playback across web, smart TVs, and set-top boxes. Design clean APIs, implement video playback components (MSE/EME/DRM), optimize reliability and performance, collaborate with cross-functional teams, and support operations to ensure high-quality streaming for millions of users.

Design, implement, and maintain software test capabilities for tactical systems. Perform full software lifecycle tasks—requirements, architecture, design, code, test, integration, documentation—and integrate test equipment and emulation infrastructure. Develop automated tests for embedded Linux, C/C++, Python and support containerized deployments. Collaborate across teams, maintain on-site presence, and support lab and production environments for mission-focused systems.

The Principal Software Test Engineer will lead software testing initiatives, mentor junior engineers, and oversee testing strategies while ensuring quality across complex aerospace software systems.

Architect and implement enterprise GenAI platforms (RAG and agentic systems), design knowledge retrieval, orchestration, tool-using agents and human-in-the-loop workflows, ensure production readiness and governance with product/data/security teams, define platform engineering best practices, and solve complex platform challenges with broad autonomy.

Lead technical direction and architecture for mobile and enterprise solutions, remain hands‑on in critical systems, mentor senior engineers, drive CI/CD/DevSecOps, evaluate and integrate vendor and AI technologies, and establish engineering standards to improve quality, reliability, and delivery across programs.

Lead a small AI-First engineering team to design, orchestrate, and verify agent-driven development workflows. Define agent toolchains, context engineering, and governance; architect full-stack applications; enforce multi-layer verification and automated QA; mentor engineers; optimize token/cost; and continuously improve AI-assisted SDLC practices and standards.