ML Engineer (Recommendation Systems)

TL;DR

ML Engineer (Recommendation Systems): Designing and optimizing recommendation systems for the LLM era to provide personalized user experiences with an accent on user modeling and ranking. Focus on integrating LLMs into personalization pipelines and building evaluation foundations for continual learning.

Location: San Francisco; Palo Alto

Compensation: $220K – $405K

Company

Perplexity builds AI-native tools to help users find answers, make consequential decisions, and complete ambitious work.

What you will do

• Own the personalization and ranking behind key product surfaces to drive core user and business metrics.
• Build user modeling that captures intent, preference, and propensity for more relevant experiences.
• Design the decision layer that balances competing objectives to produce the best overall user experience.
• Build data and evaluation foundations that enable systems to learn and improve with usage.
• Help shape the technical direction of ranking, recommendations, and personalization.

Requirements

• Deep, hands-on experience building production recommendation, ranking, or personalization systems at scale.
• Strong ML fundamentals in engagement modeling, model calibration, and online experimentation.
• Experience integrating LLMs into ranking, retrieval, or personalization pipelines.
• Strong judgment for personalization within an LLM-native product environment.
• For tech leadership roles: prior experience setting technical direction for ranking projects.

Nice to have

• Experience with large-scale ranking and training infrastructure, including feature stores and real-time serving.
• Background in user understanding, feed ranking, notifications, growth, or lifecycle modeling.

Culture & Benefits

• Comprehensive U.S. benefits including health, dental, vision, retirement, and fitness accounts.
• Equity offers for employees.
• Tailored benefits programs for employees based outside the U.S.
• Culture rooted in craftsmanship, ownership, entrepreneurship, and scholarship.