AI Researcher

Perplexity is seeking top-tier AI Research Scientists and Engineers to advance our AI products and capabilities. We're building the future of AI-powered search and agent experiences through our Sonar models, Deep Research Agent, Comet Agent, and Search products. Join us in creating SOTA experiences that handle hundreds of millions of queries and continue to scale rapidly.Team StructureDepending on your interests and expertise, you'll work on one of three specialized teams:1. Core Research Team (Horizontal)Focus on generating and improving base models that power all our products. This team works on foundational model capabilities, post-training techniques, building RL infra and infrastructure that benefits the entire organization.2. Agent Products Team (Vertical)Concentrate on fine-tuning and optimizing models for our Deep Research Agent and Labs/Canvas products. This team bridges research and product, ensuring our agent capabilities deliver exceptional user experiences.3. Comet Agent Team (Vertical)Dedicated to developing and enhancing our Comet Agent product. This specialized team focuses on the unique requirements and optimizations needed for Comet's specific use cases.ResponsibilitiesResearch & DevelopmentPost-train SOTA LLMs using the latest supervised and reinforcement learning techniques (SFT/DPO/GRPO)Leverage our rich query/answer dataset to scale model performance across Sonar, Deep Research, Comet, and Search productsStay current with the latest LLM research, especially in model training, optimization, and personalization techniquesImplement preference optimization and personalization capabilities to enhance user experienceInvent in-house improvements and optimizations to enhance SOTA modelsTurn research ideas into algorithms and run experiments to launch new modelsInfrastructure & ImplementationOwn full-stack data, training, and evaluation pipelines required for model developmentBuild robust and effective training frameworks (on top of Megatron/PyTorch) for post-training LLMsImplement necessary infrastructure and components to support cutting-edge model training at scaleIntegrate models seamlessly into our product ecosystemCollaborationWork closely with engineering teams to integrate models into Perplexity's product suiteCollaborate across teams to ensure cohesive AI experiences throughout our platformPartner with product teams to understand user needs and translate them into model improvementsQualificationsRequiredProven experience with large-scale LLMs and Deep Learning systemsStrong programming skills in Python/PyTorch; versatility is a plusExperience with post-training techniques and reinforcement learningSelf-starter with a willingness to take ownership of tasksPassion for tackling challenging problemsMinimum 2-6 years of experience on relevant projects (depending on seniority level)Nice-to-havePhD in Machine Learning, AI, Systems, or related areasExperience in post-training LLMs with SFT/DPO/GRPOC++/CUDA programming skillsExperience building LLM training frameworksAcademic publications and research impactExperience with agent systems and multi-step reasoningBackground in personalization and preference learning