Member of Technical Staff (Model Behavior Architect)

ABOUT THE ROLE We're looking for a Model Behavior Architect to help build Perplexity's AI products and evaluations. You'll sit within our AI team and collaborate closely with research and product teams, designing prompt and context engineering strategies to deliver high quality user experiences across multiple domains and models. This role is equal parts craft and science. You'll develop a deep understanding of our answer engine by pressure-testing model capabilities and working across our AI infrastructure (including system and tool prompts, skills, and evaluations) to create a stellar product experience for our users. You'll serve as a go-to expert on prompting, model quality, and behavioral consistency across new product features and model releases. KEY RESPONSIBILITIES - Context Engineering: Design, test, and optimize context strategies and system prompts that shape answer engine behavior across products, features, and use cases. - Evaluation Systems: Build automated and semi-automated evaluation pipelines that measure model quality, catch regressions, and scale across product surfaces. - Model Launch Support: Partner with research and engineering to validate model behavior before and during rollouts, ensuring smooth transitions with no degradation. - Research & Analysis: Identify inconsistencies and failure modes in model outputs through well-designed research projects —...