Principal Engineer, LLM Application Development

About RentSpree

RentSpree is the nation's leading home rental software. Our award-winning product suite simplifies the entire rental journey—from applications and screening to payments and lease management. Our mission is to bring transparency, efficiency, and trust to agents, landlords, and renters alike.

With over 4 million users, partnerships with 300+ leading real estate companies and MLS platforms, and nine years of consistent growth, RentSpree is at the forefront of proptech innovation. Our award-winning solutions deliver automation and real-time insights that make renting faster, easier, and more secure for our customers.

RentSpree is a proud Forbes' Best Startup Employer and we were also ranked one of BuiltIn Seattle’s Best Places to Work. As one of the fastest-growing property tech startups in the U.S., we’re looking for talented problem-solvers to contribute meaningful impact as we scale. 

Principal Engineer, LLM Application Development - Seattle, WA (hybrid)

We are seeking an exceptional Principal Engineer to lead the development, deployment, and ongoing evolution of cutting-edge generative AI and large-language-model (LLM) powered applications. This role sits at the intersection of deep technical ownership and cross-organizational leadership — driving best practices, architectural vision, and production-grade execution as we integrate AI capabilities into core products.

As our AI Principal Engineer, you will be a cultural and technical leader championing the next era of AI-powered feature development. You will shape how AI is adopted across the engineering organization, mentor engineers, and ensure the quality, reliability, and compliance of mission-critical LLM systems.

What You'll Do

• Technical Leadership & Execution
• • Architect, build, and scale complex AI/LLM-driven applications, including workflows, agentic loops, tool-augmented reasoning systems, and other advanced generative AI integrations.
  • Write high-quality, maintainable, and well-tested code that ships to production and evolves through iterative releases.
  • Define core AI architecture patterns, standards, and reusable frameworks to accelerate AI feature delivery across teams.
  • Continuously refine AI tooling and developer workflows for efficiency, quality, and reliability.
• Evaluation, Quality & Compliance
• • Establish and lead robust evaluation frameworks to assess model performance, guardrails, safety, fairness, and compliance.
  • Collaborate with cross-functional stakeholders (Security, Legal, Product, Data) to ensure AI features meet ethical, privacy, and regulatory requirements.
• Mentorship & Thought Leadership
• • Serve as a role model and coach, uplifting engineering excellence and AI fluency across the organization.
  • Evangelize best practices for building, validating, and maintaining LLM-based systems.
  • Drive adoption of AI-first software development tools and processes within teams.
• Product & Collaboration
• • Partner with Product, Design, and Data Science to define high-impact AI use cases and deliver them with pragmatic execution.
  • Translate complex technical concepts into clear guidance for non-technical audiences.
  • Balance long-term architectural investments with short-term delivery needs.
    
    

Our job descriptions evolve with our business needs and priorities. In addition to the description above, your role may include additional tasks, projects and team support as needed.

Skills You Bring

You’re an experienced engineer with a deep understanding of both software engineering fundamentals and modern AI/ML systems. You have a track record of turning experimental models into reliable, production-ready applications that deliver real value to users. You thrive in ambiguity, drive clarity, and elevate those around you.

Required:

• 10+ years of professional software engineering experience with a strong record of technical leadership
• Expertise building and shipping LLM applications and workflows at scale.
• Demonstrated experience designing agentic systems and/or orchestration loops that integrate multiple AI capabilities and external tools.