Principal Software Engineer - Tysons, VA

Principal Software Engineer

Do you love working with connected devices, automation, and real-world systems? Have you automated your own home, built integrations across smart devices, or thought deeply about how cloud software should control physical systems reliably?

We are looking for a versatile Principal Software Engineer to help lead architecture and engineering for our software engineering team building software for IoT, smart home automation, energy management, HVAC, water, and connected-device control experiences. This role is an IC role that sits at the intersection of cloud services, physical devices, mobile and web applications, automation logic, data processing, and customer-facing product experiences.

As a Principal Software Engineer, you will provide hands-on technical leadership across teams. You will help define architecture, guide major design decisions, mentor engineers, and lead the evolution of systems that must be reliable, scalable, maintainable, and adaptable as our connected-device platform continues to grow.

We combine the product breadth and technical scale of a mature connected-device platform with the collaborative culture of a smaller engineering organization. This role is ideal for someone who wants to work across software, hardware, data, and product domains while helping shape systems used by millions of customers.

What You’ll Do

As a Principal Software Engineer, you will help design and evolve systems that coordinate physical devices, cloud services, mobile and web applications, automation engines, partner integrations, and data pipelines. You will work across product, firmware, platform, operations, and application engineering teams to turn ambiguous business and technical needs into reliable, scalable, and maintainable software systems.

You will be expected to lead through technical depth, sound judgment, and influence. You will own important architecture decisions, guide implementation strategy, and help engineers across multiple teams build better systems.

Day-to-Day Responsibilities

• Provide hands-on technical leadership for systems spanning IoT device control, smart home automation, energy, HVAC, water, and connected-device experiences.
• Lead architecture and design for major software components, services, APIs, data flows, and integration patterns.
• Help evolve existing monolithic systems into more modular, scalable, reliable, and maintainable systems.
• Partner with product, firmware, platform, operations, and application teams to turn ambiguous needs into clear technical direction.
• Mentor engineers at multiple levels and help raise the technical bar through design reviews, code reviews, technical guidance, and reusable patterns.
• Drive cross-team collaboration and execution across multiple technical domains.
• Evaluate new technologies, frameworks, and methodologies where they can materially improve product capabilities or engineering outcomes.
• Reason across the full product stack, including backend services, databases, APIs, web and mobile experiences, device integrations, automation logic, and operational tooling.
• Be an expert on system architecture, functionality, data flows, operational processes, and the tools needed to operate production systems effectively.
• Provide technical thought leadership for major software components, systems, and features, earning alignment and driving adoption across teams.
• Exercise strong engineering judgment: know when to move quickly, when to invest in a robust platform capability, and when to avoid unnecessary complexity.
• Bring your ideas. We want our engineers to collaborate on product development, not blindly build to a spec.
• Other duties as assigned.

What You Need

• Bachelor’s degree in Computer Science, Computer Engineering, a related field, or equivalent professional experience.
• 15+ years of professional software development experience.
• Proven experience designing, building, and delivering complex software systems.
• Strong object-oriented programming skills; experience with C#/.NET or a similar object-oriented language is required; direct C# and .NET experience would be a major plus.
• Significant database design, performance, and development experience.
• Experience leading technical direction across teams and influencing architecture beyond a single project or codebase.
• Experience mentoring engineers and helping develop people, practices, and reusable technical solutions.
• Ability to select appropriate frameworks, architecture patterns, and technical approaches, then educate teams and drive adoption.
• Strong analytical skills and a practical problem-solving mindset.
• Ability to lead and influence across teams without relying solely on reporting authority.
• Ability to reason across the full product stack, including backend services, data stores, APIs, device integrations, and web/mobile user experiences.
• Strong understanding of object-oriented design, software development lifecycles, and long-term maintainability concerns.
• Excellent communication skills, including the ability to explain technical tradeoffs to engineers, product owners, and business stakeholders.

Experience That Would Be a Major Plus

• Experience with IoT, smart home, energy management, HVAC, water, automation, or connected-device systems.
• Experience working with physical systems, hardware devices, firmware teams, or embedded-device integrations.
• Experience with event-driven systems, device telemetry, automation/rules engines, or distributed systems.
• Experience in modernizing monolithic systems or decomposing systems into modular services.
• Experience designing systems where cloud software interacts with deployed physical devices and must account for latency, reliability, compatibility, and operational visibility.