Who we are At CarGurus (NASDAQ: CARG), our mission is to give people the power to reach their destination. We started as a small team of developers determined to bring trust and transparency to car shopping. Since then, our history of innovation and go-to-market acceleration has driven industry-leading growth. In fact, we’re the largest and fastest-growing automotive marketplace, and we’ve been profitable for over 15 years. What we do The market is evolving, and we are too, moving the entire automotive journey online and guiding our customers through every step. That includes everything from the sale of an old car to the financing, purchase, and delivery of a new one. Today, tens of millions of consumers visit CarGurus.com each month, and ~30,000 dealerships use our products. But they're not the only ones who love CarGurus—our employees do, too. We have a people-first culture that fosters kindness, collaboration, and innovation, and empowers our Gurus with tools to fuel their career growth. Disrupting a trillion-dollar industry requires fresh and diverse perspectives. Come join us for the ride! Role overview CarGurus is hiring for a Senior Principal Software Engineer in our Consumer Commerce department – the group responsible for our highest trafficked pages and products. Our mission is to deliver comprehensive, accurate, and engaging vehicle information, fostering trust and driving informed and high-intent consumer decisions, while upholding CarGurus’ standards for innovation, user-centricity, and technical excellence.  In this role, you’ll contribute to high‑visibility parts of our site, introduce AI to our consumer experiences, and collaborate closely with partners in Product, UX, and Analytics. This is a fast-moving, impact-oriented environment where you will set technical direction across the department, mentor engineers, and drive high-visibility AI initiatives from concept to production at scale.   What you'll do * Design, build, and deploy consumer-facing experiences end-to-end to 45 million monthly visitors, from the data and model layer through to the user-facing product, being hands-on and actively participating in the implementation of select initiatives * Serve as a go-to AI expert and advisor for all Consumer AI projects, providing technical guidance on architecture, design, and implementation choices * Guide the platform and infrastructure decisions underpinning AI deployments, including storage, memory, request handling and load, evaluation pipelines, observability and analytics * Evaluate the broader AI framework and tooling landscape, independent of any single language or ecosystem, and guide teams toward the right approach for a given problem; develop proof-of-concepts to validate AI approaches and clearly explain the trade-offs between different technologies * Build and operate systems using LangChain, LangGraph, and Langfuse in Python to develop, orchestrate, and evaluate agentic and LLM-based applications in production * Drive the department's adoption of fully agentic programming, defining the patterns, tooling, and best practices engineers follow when building agentic systems * Partner with engineering leadership, product, and data teams to shape phased platform guidelines and roadmaps for consumer initiatives * Mentor engineers across teams on system design, evaluation methodology, and operational best practices * Conduct workshops and produce documentation on AI development, deployment, monitoring, and support practices across multiple teams * Document architectural decisions in Architecture Decision Records (ADRs) and share findings and best practices across teams   What you'll bring * 10+ years of experience architecting resilient, scalable systems and leading technical direction across multiple teams with extensive experience designing, implementing, and deploying consumer-facing AI experiences in production * Hands-on experience with LangChain, LangGraph, and LangFuse in Python and with the platform and infrastructure layers of AI systems, including storage, memory, load management, evaluations, and observability * Broad knowledge of the AI framework and tooling landscape beyond Python, with the ability to evaluate and recommend approaches independent of language or ecosystem * Hands-on full stack experience building well-structured, performant applications across frontend, backend, and the platform and infrastructure layers for production-grade systems, including experience building APIs and REST services in Java and UX applications in React preferred * Strong communicator with a collaborative spirit who can influence technical direction across multiple teams and disciplines * Experience working within the AWS ecosystem a plus * Experience with agentic programming and multi-agent workflows, including guiding teams through adoption of these approaches * Experience defining engineering patterns and standards that others adopt, and mentoring engineers on architecture and coding practices   The displayed range represents the expected annual base salary / On-Target Earnings (OTE) for this position. On-Target Earnings (OTE) is inclusive of base salary and on-target commission earnings, which applies exclusively to sales roles. Individual pay within this range is determined by work location and other factors such as job-related skills, experience, and relevant education or training. This annual base salary forms part of a comprehensive Total Rewards Package. In addition to benefits, this role may qualify for discretionary bonuses/incentives and Restricted Stock Units (RSUs). Position Pay Range $191,000—$239,000 USD Working at CarGurus We reward our Gurus’ curiosity and passion with best-in-class benefits and compensation, including equity for all employees, both when they start and as they continue to grow with us. Our career development and corporate giving programs, as well as our employee resource groups (ERGs) and communities, help people build connections while making an impact in personally meaningful ways. A flexible hybrid model and robust time off policies encourage work-life balance and individual well-being. Thoughtful perks like daily free lunch, a new car discount, meditation and fitness apps, commuting cost coverage, and more help our people create space for what matters most in their personal and professional lives. CarGurus may require in-person interviews as part of our hiring process, particularly for positions based in our Boston and Dublin offices. Candidates selected for an in-person interview will be notified in advance. Please be aware that travel expenses are the responsibility of the candidate. We welcome all CarGurus strives to be a place to which people can bring the ultimate expression of themselves and their potential—starting with our hiring process. We do not discriminate based on race, color, religion, national origin, age, sex, marital status, ancestry, physical or mental disability, veteran status, gender identity, or sexual orientation. We foster an inclusive environment that values people for their skills, experiences, and unique perspectives. That’s why we hope you’ll apply even if you don’t check every box listed in the job description. We also encourage you to tell your recruiter if you require accommodations to participate in our hiring process due to a disability so we can provide the appropriate support. We want to know what only you can bring to CarGurus. #LI-Hybrid