Member of Technical Staff (AI Researcher)

About the Company

Perplexity is building the future of AI-powered search and agent experiences through Sonar models, Deep Research Agent, Comet Agent, and Search products, handling hundreds of millions of queries.

Responsibilities

• Post-train SOTA LLMs using supervised and reinforcement learning techniques (SFT/DPO/GRPO)
• Leverage query/answer datasets to scale model performance across products
• Stay current with latest LLM research in model training, optimization, and personalization
• Implement preference optimization and personalization capabilities
• Turn research ideas into algorithms and run experiments to launch new models
• Own full-stack data, training, and evaluation pipelines
• Build robust training frameworks on top of Megatron/PyTorch
• Collaborate with engineering and product teams to integrate models into the product suite

Requirements

• Proven experience with large-scale LLMs and Deep Learning systems
• Strong programming skills in Python and PyTorch
• Experience with post-training techniques and reinforcement learning
• 2-6 years of experience on relevant projects depending on seniority
• Self-starter with a passion for tackling challenging problems

Preferred Qualifications

• PhD in Machine Learning, AI, Systems, or related areas
• Experience in post-training LLMs with SFT/DPO/GRPO
• C++/CUDA programming skills
• Experience building LLM training frameworks
• Academic publications and research impact
• Experience with agent systems and multi-step reasoning
• Background in personalization and preference learning