Top Principal Software Engineer Jobs in Denver & Boulder, CO

Principal Software Engineer responsible for designing and developing enterprise software, making architectural and technical decisions, maintaining shared infrastructure and components, and improving security, performance, and reliability. The role mentors developers, establishes engineering standards, collaborates with product and design teams, supports existing products, troubleshoots complex issues, contributes to CI/CD and cloud initiatives, and works directly with customers and distributed teams.

Designs, architects, develops, tests, and troubleshoots complex software applications for space systems. The role includes writing scalable and maintainable code, conducting unit tests and code reviews, documenting software processes, using version control, and applying advanced algorithms and software engineering practices. Provides technical leadership and mentorship, collaborates with engineering teams, and supports large-scale software projects while maintaining secure, high-quality development standards.

Leads the architecture, design, development, integration, verification, and testing of complex software and multidisciplinary space systems. Responsibilities include managing system requirements and architectures, defining operational concepts, leading milestone reviews, mitigating technical risks, improving engineering processes, and mentoring software engineers. The role requires advanced software engineering expertise, scalable system design, algorithmic knowledge, technical leadership, and an active Top Secret clearance.

As a Senior Principal Engineer, you'll define and drive the technical strategy for customer experience platforms, lead architectural decisions, and mentor engineering teams to enhance customer and agent experiences.

Design, build, deploy, and maintain resilient, scalable production systems for Toast’s retail customers. The role sets long-term technical architecture and strategy, communicates technical direction, mentors senior engineers, improves engineering productivity, diagnoses performance issues, and drives initiatives amid ambiguity. Engineers collaborate directly with retail customers, visit stores, understand operational workflows, and use AI tools to improve development velocity and quality.

Lead architecture and technical execution for Toast’s Payroll and Team Management products. Own authentication, authorization, and organizational hierarchy across a multi-tenant SaaS platform. Drive high-scale, full-stack initiatives, modern agentic development practices, integrations, technical strategy, quality standards, deployment practices, and cross-functional collaboration. Mentor engineers across teams and leverage AI tools and LLM integration to improve software development velocity and quality.

Design, develop, and maintain a native IBM i connectivity agent for Redwood RunMyJobs. Responsibilities include job submission and monitoring, spool and queue handling, CL/RPG invocation, security integration, API connectivity, troubleshooting, performance and reliability improvements, architecture, code reviews, testing, documentation, and collaboration with product and engineering teams. The role also requires validating AI-assisted solutions against authoritative IBM i documentation.

Build and maintain a Java-based connectivity agent integrating Redwood RunMyJobs with IBM z/OS. Responsibilities include JES, TSO, SMF, USS, security, cryptography, custom protocols, C/JNI integration, concurrency, troubleshooting, performance, architecture, testing, documentation, and collaboration. The role requires deep mainframe systems expertise, strong Java and C skills, DevOps experience, and sound judgment when using AI-assisted engineering tools.

Lead design and implementation of embedded OS layer software and platform infrastructure. Develop Yocto-based embedded Linux distributions, BSPs, hypervisors, device drivers, CI/CD pipelines, and security features (secure boot, OTA). Act as platform point of contact, collaborate with product teams, and produce engineering policies and documentation.

Leads architecture and development of Azure Storage table, metadata, and indexing systems at massive cloud scale. Designs distributed-system primitives for partitioning, indexing, transactions, consistency, replication, caching, and high-performance data access. Drives architectural decisions, prototypes innovations through production, and improves performance, scalability, reliability, and cost efficiency. Requires deep expertise in distributed storage, databases, or large-scale systems.

Designs and leads large-scale software subsystems, architecture, coding standards, code reviews, debugging tools, performance optimization, refactoring, and QA automation. Guides business and technical solution definition, evaluates production readiness using objective metrics, and develops web content management, workflow automation, integrations, and database solutions. The role is telecommuting eligible throughout the United States.

Define architectural direction for Azure Specialized platform services and lead the design of highly available distributed cloud systems. Drive reliability, scalability, observability, security, diagnostics, and operational improvements across engineering organizations. Establish service health frameworks, SLOs, metrics, and governance for mission-critical services. Mentor engineers, influence technical strategy, resolve complex cross-system challenges, and advance AI-assisted troubleshooting and platform modernization.

Work with customers and cross-functional teams to design, build, and deliver cloud-based solutions. Lead design, identify dependencies, mentor engineers, act as DRI and on-call, and improve availability, reliability, observability, and performance. Contribute to open-source assets and collaborate with Microsoft product teams to produce extensible, maintainable code and scalable solution patterns.

Design and implement PostgreSQL internals, indexing, query engine extensions, and storage-layer features to support large-scale document workloads on Azure. Profile distributed systems, tune performance, collaborate with open-source communities, conduct design/code reviews, and drive cross-team alignment for mission-critical database features.

Own the architecture, implementation, and operational excellence of major Azure Boost DPU software components. Develop low-level systems software spanning operating systems, virtualization, networking, storage, device management, and hardware interfaces. Lead complex cross-functional initiatives, optimize hyperscale performance and reliability, resolve system-level issues, establish engineering practices, influence platform architecture, and mentor engineers across Azure infrastructure teams.

Lead development and operation of a scalable Kubernetes-based cloud-native platform. Shape the engineering roadmap, deliver enterprise platform capabilities, establish best practices, mentor engineers, and collaborate across Agile teams. Build highly available and fault-tolerant production services using Kubernetes and cloud-native technologies, while applying expertise in Go, Python or Bash, networking, Linux, and CI/CD practices.

Design and build Azure Kubernetes Service features and AI-native infrastructure, improve service reliability and developer velocity, automate incident prevention/remediation, integrate AI tools, and operate distributed, containerized systems at cloud scale.

Develops and maintains high-quality systems software and microservices for Azure Messaging services, including data storage and replication. Drives product and engineering-process innovation, applies AI to software development, ensures software quality and stability, and uses rigorous development practices including requirements, testing, and efficient coding techniques.

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.

Define technical direction for hyperscale Azure Storage components; architect, develop, test, and support highly scalable, secure, compliant, and highly available cloud services. Lead multiple engineering projects, improve reliability, scalability, performance, consistency, and observability, and apply AIOps for incident detection, root-cause analysis, and operational excellence.

Lead design and implementation of large-scale Pub/Sub and messaging services within Azure Event Grid/Microsoft Fabric. Define scalable, reliable architectures, drive testing and CI/CD automation, build developer tooling, mentor engineers, manage incident response and operational excellence, and collaborate with PMs, EMs, researchers, and customers to deliver production-ready cloud services.

Lead architecture and hands-on development for Microsoft's virtualization platform, focusing on hypervisor and VMM capabilities. Design, implement, and optimize systems software across Windows, Linux, macOS, Azure, and containers. Improve performance, security, reliability, testing, and operational readiness; diagnose low-level hardware/software issues; enable virtualization on new silicon; mentor engineers; and influence platform strategy across teams and hardware partners.

Leads software architecture, development, testing, integration, and delivery for mission-critical spacecraft flight and ground systems. Designs embedded flight software, hardware drivers, RTOS applications, and web-based ground platforms; supports hardware-in-the-loop validation and on-orbit operations. Provides technical leadership, mentorship, and stakeholder guidance for a major constellation program. Requires extensive aerospace or defense software experience, embedded systems expertise, C/C++, Python, hardware integration, RF communications, U.S. citizenship, and an active TS/SCI clearance.

Designs, develops, configures, and supports Edifecs healthcare EDI solutions and transaction mappings. Works with 837, 834, 835, 820, and 270/271 transactions; troubleshoots transmissions, configures validations, and develops Groovy scripts. Leads Agile and DevOps efforts, mentors engineers, supports QA, and designs scalable AWS applications using containers, microservices, and CI/CD. Provides technical leadership, architecture guidance, performance tuning, and stakeholder consultation.

Leads the technical vision, architecture, and execution of AI performance, framework, benchmarking, and developer-productivity initiatives. Drives cross-team architecture, resolves complex systems trade-offs, mentors technical leaders, and contributes hands-on through prototyping, implementation, reviews, debugging, observability, and automation. Delivers measurable improvements in model onboarding speed, runtime performance, reliability, hardware utilization, and Azure capacity efficiency across models, frameworks, compilers, runtimes, systems, services, and hardware.