Member of Technical Staff (AI Researcher) at Perplexity (San Francisco)
Job Description
Perplexity is hiring AI research scientists and engineers in San Francisco to post-train state-of-the-art language models with supervised and reinforcement learning, using its large query-and-answer data to improve Sonar, Deep Research, Comet and Search.
At a glance
- Role: Member of Technical Staff (AI Researcher)
- Where: San Francisco, California, USA
- Pay: US$220,000–485,000, with equity
- Experience: 2–6 years on relevant projects, depending on level
- Apply: open until filled (re-checked 12 October 2026)
About the AI researcher role
- Post-train state-of-the-art LLMs using supervised and reinforcement learning (SFT, DPO, GRPO)
- Use Perplexity’s query-and-answer data to scale model performance across its products, including preference optimisation and personalisation
- Turn research ideas into algorithms and run experiments that lead to new model launches
- Own data, training and evaluation pipelines, and build training frameworks on Megatron and PyTorch
- Work with engineering teams to integrate models into products
Researchers join one of three teams: Core Research, which improves the base models and post-training infrastructure used everywhere; Agent Products, which tunes models for Deep Research and Labs; or the Comet Agent team.
What Perplexity is looking for
- Proven experience with large-scale LLMs and deep learning systems
- Strong Python and PyTorch
- Experience with post-training techniques and reinforcement learning
- A self-starter who takes ownership, with 2–6 years of relevant experience depending on level
Nice to have
- A PhD in machine learning, AI, systems or related areas
- Post-training LLMs with SFT, DPO or GRPO
- C++/CUDA and experience building LLM training frameworks
- Publications, agent systems and multi-step reasoning, personalisation and preference learning
Pay and location
Perplexity lists pay of US$220,000–485,000, with equity. The role is based in San Francisco.
How to apply
Apply through the official Perplexity job posting. Perplexity’s posting does not give a closing date, so the role is open until filled; ResearchJobs.in will re-check this listing on 12 October 2026. Check the posting for location and work-authorisation details before you apply.
See all our artificial intelligence jobs, or browse more research jobs on ResearchJobs.in.
Hiring institution: Perplexity
Official advertisement: jobs.ashbyhq.com
How to prepare for this application
- RL for LLMs: be ready to compare DPO and GRPO and when each works.
- Search data: think about how query-answer logs could become training signal without leaking private data.
- Infrastructure: discuss post-training at scale on Megatron or similar.
- Evaluation: how would you tell whether a new model improved answer quality for users?
- Team fit: say which of the three teams you are aiming for and why.
About Perplexity
Perplexity builds AI-powered search and agent products, including its Sonar models, Deep Research Agent, Comet Agent and Search, which handle hundreds of millions of queries and are growing rapidly.
