Member of Technical Staff (AI Researcher)

Perplexity is seeking top-tier AI Research Scientists and Engineers to advance AI products and capabilities. You'll work on one of three specialized teams: Core Research (foundational model capabilities and post-training), Agent Products (fine-tuning models for Deep Research Agent and Labs/Canvas), or Comet Agent (developing and enhancing the Comet Agent product).

What you'll do

• Post-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 products
• Own full-stack data, training, and evaluation pipelines required for model development
• Build robust and effective training frameworks (on top of Megatron/PyTorch) for post-training LLMs
• Implement preference optimization and personalization capabilities to enhance user experience
• Turn research ideas into algorithms and run experiments to launch new models
• Work closely with engineering and product teams to integrate models into Perplexity's product suite

What you'll need

• Proven experience with large-scale LLMs and Deep Learning systems
• Strong programming skills in Python/PyTorch; versatility is a plus
• Experience with post-training techniques and reinforcement learning
• Self-starter with a willingness to take ownership of tasks
• Minimum 2-6 years of experience on relevant projects (depending on seniority level)

Nice to have

• 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