Senior AI Developer – LLM Fine-Tuning & Generative AI

Airbnb was born in 2007 when two hosts welcomed three guests to their San Francisco home, and has since grown to over 5 million hosts who have welcomed over 2 billion guest arrivals in almost every country across the globe. Every day, hosts offer unique stays and experiences that make it possible for guests to connect with communities in a more authentic way. The Community You Will Join: Machine Learning and Artificial Intelligence are at the heart of the Airbnb product. From Trust to Payments, and from Customer Service to Marketing we rely on ML to ensure that guests and hosts have the best possible experience with Airbnb.  The CS AI product team is responsible for driving CSxAI (Customer Support x Artificial Intelligence) initiatives by adopting the Generative AI technologies to enable an intelligent, scalable and exceptional service experience. The team develops and enhances various AI models, ML services and tools including LLM fine-tuning, alignment and optimization, RAG/Search,  LLM evaluation and testing automation, feedback-based learning and guardrail for a wide range of applications in Airbnb. The Difference You Will Make: As a principle machine learning engineer, you will be responsible for fine-tuning state-of-the-art LLMs for diverse use cases while optimizing models for high-performance deployment on Airbnb’s ML Infrastructure. You will partner with product managers, software engineers, data scientists and operation teams to brainstorm, design and develop AI products such as AI Assistant, Autonomous agent,  recommendation, travel planning, and many more products that make meaningful impacts in the world of travel. A Typical Day:  * Work with large scale structured and unstructured data; explore, experiment, build and continuously improve foundation models for Airbnb product, business and operational use cases. * Create a multi-year tech roadmap that enables our team to stay on the leading edge of the rapidly evolving AI landscape and leverage the best in class technologies to deliver customer benefits. * Continuously evaluate recent and upcoming large foundational models, ensuring the selection and refinement of the highest quality models for enhanced performance and efficiency. * Hands-on prototype, develop and productionize LLM models and pipelines at scale, including both batch and real-time use cases. * Drive key AI architectural decisions for products, and contribute to Airbnb’s ML platform architecture and strategy. Your Expertise: * PhD in Computer Science,  Machine Learning, Mathematics, Statistics, or related technical field. * 10+ years of experience with developing machine learning models and products at scale from inception to business impact. * Programming experience in Python and hands-on experience with frameworks such as PyTorch. * Proven record of training, fine tuning, optimizing models and inference run-time * Post-training experience in areas like data processing for fine-tuning; responsible LLMs; LLM alignment; reinforcement learning; efficient training and inference; language model evaluation; and/or multilingual and multimodal modeling. * Or specialized experience in runtime optimizations, model quantization, compression, on-device inference, GPU inference, pytorch, kernel development Your Location: This position is US - Remote Eligible. The role may include occasional work at an Airbnb office or attendance at offsites, as agreed to with your manager. While the position is Remote Eligible, you must live in a state where Airbnb, Inc. has a registered entity. Click here for the up-to-date list of excluded states. This list is continuously evolving, so please check back with us if the state you live in is on the exclusion list. If your position is employed by another Airbnb entity, your recruiter will inform you what states you are eligible to work from. Our Commitment To Inclusion & Belonging: Airbnb is committed to working with the broadest talent pool possible. We believe diverse ideas foster innovation and engagement, and allow us to attract creatively-led people, and to develop the best products, services and solutions. All qualified individuals are encouraged to apply. We strive to also provide a disability inclusive application and interview process. If you are a candidate with a disability and require reasonable accommodation in order to submit an application, please contact us at: reasonableaccommodations@airbnb.com. Please include your full name, the role you’re applying for and the accommodation necessary to assist you with the recruiting process.  We ask that you only reach out to us if you are a candidate whose disability prevents you from being able to complete our online application. How We'll Take Care of You: Our job titles may span more than one career level. The actual base pay is dependent upon many factors, such as: training, transferable skills, work experience, business needs and market demands. The base pay range is subject to change and may be modified in the future. This role may also be eligible for bonus, equity, benefits, and Employee Travel Credits.   Pay Range $248,000—$310,000 USD

About us: Causaly is redefining how humans acquire knowledge and develop insights in biomedicine. Our AI-powered platform enables researchers and decision-makers to discover and interpret evidence from millions of scientific publications, clinical trials, regulatory documents, and other complex data sources in minutes. We are building the world’s most advanced biomedical knowledge platform, powered by a high-precision Knowledge Graph and GenAI capabilities. Our technology is already used by leading biopharmaceutical organizations to accelerate drug discovery, improve safety, and drive better decision-making. Backed by top-tier investors including ICONIQ, Index Ventures, Pentech, and Marathon, we are scaling rapidly and expanding our product suite and market presence.  ABOUT THE TEAM We’re hiring AI engineers to help us transform research outcomes in biomedical sciences. We utilise generative AI and agents to help scientists find novel connections and insights from biomedical literature and datasets. Delivering a faster research experience is not just a matter of picking the latest LLM model. Getting accurate, scientifically relevant, trustworthy and meaningful results relies on building trust with our users that comes from integrating proper levels of guardrails, biomedical curation, consistent update cycles and robust deployment practices that make our platform a one-stop shop for a researcher’s needs. We’re looking for AI engineers who will champion this cause and help us apply AI to transform the way biomedical professionals carry out their research and day-to-day exploration. WHAT YOU’LL BE DOING · Design and implement ML/AI solutions end-to-end, from the idea and data exploration phase to deployment and monitoring, balancing cutting-edge techniques with pragmatism to deliver measurable impact. · Apply strong software engineering principles, such as modularity, testing, code reviews, CI/CD and observability, to ensure AI systems are reliable, maintainable, production-ready and can be readily adapted to future developments. · Choose the right approach for the problem at hand, evaluating classical ML and NLP techniques, LLM-based solutions, and agentic solutions to balance trade-offs between speed, cost, complexity, interpretability, and performance. · Collaborate closely with product, design, and other engineering teams to scope work, align on success metrics, and incrementally ship improvements in user-facing features powered by AI. · Document system architectures and decision rationale early and clearly, enabling alignment across teams and accelerating onboarding and iteration. · Champion model and data quality, including dataset versioning, robust evaluation, fairness/bias assessment, and real-world performance tracking. · Mentor junior AI engineers and cross-functional teammates, sharing best practices in modelling, coding, maintaining and integrating product features, and helping grow a high-trust, high-performance team culture. · Stay up-to-date with emerging research and tools, distilling key insights and bringing back relevant innovations to elevate team capabilities and product opportunities. · Contribute to a culture of knowledge sharing, through company-wide Slack channels, Show and Tell presentations and technical deep-dives. WHAT EXPERIENCE YOU’LL NEED TO BE SUCCESSFUL · A master's degree or above in Computer Science, Electrical Engineering or a related field. · 5+ years of experience building AI/ML systems in production environments, including ownership of key lifecycle stages: data collection, modeling, evaluation, deployment, and monitoring. · Proficiency in Python and modern ML and agentic frameworks such as PyTorch, TensorFlow, or LangChain, with experience packaging models into APIs or integrating them into applications. · A solid understanding of LLMs for natural language processing applications, including topics such as embeddings, prompt engineering and fine-tuning. · Strong software engineering foundations such as version control, unit/integration testing, CI/CD, containerization plus a mindset of building for reliability and scale. · Experience working in product-focused teams, collaborating with designers, engineers, and PMs, to scope and ship AI features iteratively · Ability to reason about system behavior end-to-end, including model performance, latency, and observability, and how these impact user experience. · Clear, structured communicator, comfortable documenting and defending architectural decisions and engaging in thoughtful technical debate. NOT REQUIRED, BUT IT’S A PLUS IF YOU ALSO HAVE: · Experience with MLOps/LLMOps frameworks and best practices · A PhD in Computer Science, Electrical Engineering or a related field. · A background or work experience in life-sciences, health-tech, or other data-intensive domains BENEFITS 💰 Competitive compensation package    🩺 Private medical & dental insurance   📔 Life insurance (4 x salary)    🤓 Personal development budget   🧘 Individual wellbeing budget   🌴 25 days holiday plus bank holidays   🥳 Your birthday off!  🚀 Potential to have real impact and accelerated career growth as a member of an international team that's building a transformative AI product.  We are on a mission to accelerate scientific breakthroughs for ALL humankind, and we are proud to be an equal opportunity employer. We welcome applications from all backgrounds and fairly consider qualified candidates without regard to race, ethnic or national origin, gender, gender identity or expression, sexual orientation, disability, neurodiversity, genetics, age, religion or belief, marital/civil partnership status, domestic / family status, veteran status or any other difference.