Principal Engineer, LLM Application Development

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. 

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.

• 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.

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.
• Proven ability to create evaluation frameworks that ensure safety, reliability, and compliance for LLM-based applications.
• Experience shipping multiple releases of AI-powered products from prototype through production and iteration.
• Strong engineering instincts and ability to influence architectural direction.
• Excellent communication skills with the ability to collaborate across functions.

Preferred:

• Experience with generative AI frameworks (e.g., LangChain, LlamaIndex, Vertex AI, Azure OpenAI, etc.).
• Background in distributed systems, platform engineering, or developer tooling.
• Track record of mentoring senior engineers and fostering a culture of technical excellence.
• Experience leading adoption of new development paradigms across large engineering organizations.

These encompass our guiding principles and startup culture competencies:

• Take full ownership and accountability: Drives projects from idea to execution, with pride, urgency, and a “do what it takes” mentality.
• Collaborate with clarity, candor, and respect: Communicate openly and courageously, offer and receive feedback well, and build trust through transparency and reliable partnership.
• Strive for excellence while staying humble: Driven with a bias for action, hold a high bar, think critically, and continuously look to improve.
• Bring a versatile, proactive mindset: Adapt to evolving needs, anticipate challenges, take initiative, be resourceful, and embrace opportunities to achieve high quality results.
• Innovate and learn fast: Experiment, learn from failure, and seek opportunities to introduce new methods or diverse ways of achieving results.
• Engage in healthy debate and commit as a team: Contribute ideas, challenge constructively, and align quickly for decisive action.
• AI is a core skill: Equip yourself to use AI in your daily workflow, boosting productivity, accelerating RentSpree’s growth, and building future-ready career skills in a world where AI literacy is essential.

As a fast-growing startup, our culture is built on collaboration, curiosity, and the drive to build something meaningful together. From most comprehensive benefits starting on day one to an environment built on trust, respect, and belonging, we make sure our team feels supported every step of the way. Here’s what we offer:

• Compensation: $280k – $310k base
• Equity Options: Share in the value we’re creating—your work makes a real impact.
• Team-First Culture: Join a group of talented, supportive teammates who inspire each other to do their best work and celebrate every win.
• Learning & Development: Ongoing support for your growth through resources, coaching, and career development opportunities.
• Health Coverage: Comprehensive employee + dependent medical, dental, and vision insurance, as well as HSA/FSA options. Plus, enjoy additional health perks like access to Headspace Care+, gym membership discounts, and much more — because your well-being matters, inside and out.
• Plan for your future: Life, disability, and Simple IRA retirement plan with company match to support your future.
• Flexible Vacation Policy: We trust you to take the time you need to rest and recharge.
• Holidays: Enjoy 12 holidays throughout the year, as a part of our commitment to honoring culture, history, and time to recharge. 
• Events: We make time to connect and celebrate through reimbursable weekly team lunches, game nights, events, and more, both in-person and remotely.
• Recognition Programs: Team members can recognize their peers with Sprees, which are redeemable for gift cards and/or donations to an organization of your choice, or nominate a colleague for a S.P.R.E.E. Award to spotlight above-and-beyond contributions, which may be rewarded with a spot bonus. Our Work Anniversary Program also honors employee milestones with personalized tokens of appreciation!
• Business Expense Allowance & Internet Reimbursement: Get the tools and support you need to do your best work.
• Parental Leave & Fertility Support: Inclusive benefits to support you and your family, wherever you are in life.
• Legal & tax benefits: We offer group legal benefits and tax support through RocketLawyer.
• Seattle HQ: If you’ll be working from our Seattle office, you’ll receive a company-sponsored Orca card to cover the cost of public transportation to and from the office!

We’re a team of talented, kind, and supportive people who take ownership, move with urgency, and strive for excellence. If you’re ready to roll up your sleeves and take on exciting challenges, we’d love to hear from you, even if you don’t meet every requirement!

RentSpree is an equal opportunity employer that is committed to diversity and inclusion in the workplace. We prohibit discrimination and harassment of any kind based on race, color, sex, religion, sexual orientation, national origin, disability, genetic information, pregnancy, or any other protected characteristic as outlined by federal, state, or local laws.

This policy applies to all employment practices within our organization, including hiring, recruiting, promotion, termination, layoff, recall, leave of absence, compensation, benefits, training, and apprenticeship. RentSpree makes hiring decisions based solely on qualifications, merit, and business needs at the time.