Principal Engineer: AI-Driven Discovery & Ranking

Pinterest Job Advertisements; San Francisco (CA); Hybrid; USD 243,000 - 450,000; Full time

Job summary

Pinterest is seeking a Principal Engineer to set the technical vision across Homefeed, Search, and AI Assistant, shaping how hundreds of millions of Pinners discover ideas daily. The role sits at the intersection of relevance, ranking, retrieval, and generative AI.

You will drive architecture, lead cross‑functional initiatives, and partner with product, data science, research, and design to deliver durable platform health and scalable impact.

Qualifications

• 15+ years of industry experience in large-scale systems and/or machine learning with impact in search, recommendations, feeds, or conversational AI.
• Proven experience as Principal Engineer/Architect or equivalent senior leader driving cross-org strategy and execution.
• Deep expertise in two or more core areas: retrieval/ranking, representation learning, search systems, or large language models.

Responsibilities

• Define long-term architecture for Homefeed, Search, and AI Assistant, including retrieval, ranking, personalization, and generative experiences.
• Drive multi-year roadmap to unify signals, features, and models across surfaces for a coherent discovery experience.
• Lead design/adoption of large-scale retrieval and ranking systems to improve relevance and monetization.
• Architect integration of LLMs and foundation models with the discovery stack (query understanding, content understanding, safety).
• Provide hands-on technical leadership on key projects: design components, review PRs, de-risk launches, mentor staff+ TLs.
• Partner with Product, Data Science, Research, and Design to translate bets into robust technical plans and durable platform health.

Skills

Large-scale retrieval & ranking

Representation learning

Search systems

Large language models

Architectural transformations

Cross-functional collaboration

Mentoring engineers

Executive communication

Education

Bachelor’s degree in computer science

Job description

Pinterest is seeking a Principal Engineer to set the technical vision across Homefeed, Search, and AI Assistant, shaping how hundreds of millions of Pinners discover ideas daily. The role sits at the intersection of relevance, ranking, retrieval, and generative AI.

You will drive architecture, lead cross‑functional initiatives, and partner with product, data science, research, and design to deliver durable platform health and scalable impact.