Member of Technical Staff (Data Scientist, Evals)

Perplexity·San Francisco, California, United States$200K - $300K·posted 47d ago · last seen 48m ago

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About interviewing at Perplexity

One of the few AI startups with a fully published interview guide (perplexity.ai/hub/careers/interview-guide): online application (response within two weeks) → recruiter phone screen → a technical screen that for engineers is 'usually a standard technical programming interview' → a quickly-scheduled onsite of 4–5 interviews including a hiring-manager deep dive on past work and experience anecdotes → a final interview with a Perplexity founder or leader → decision within a week of the onsite. Coding leans Python and mixes LeetCode medium–hard with practical search-flavored tasks (ranking/filtering, concurrency, data handling); system design is AI-native (RAG pipelines, retrieval at scale, LLM serving cost/latency). Applicants are judged 'solely on merit and potential impact' and must show 'frontier knowledge and excellence in at least one area'; roles are broad by default with team matching happening during the onsite, every role — managers included — is hands-on, and building AI products isn't expected but fluency in using AI tools is required. In-person 4 days/week near an office; remote is case-by-case.

Read the full Perplexity interview process →

Description

Perplexity serves tens of millions of users daily with reliable, high-quality answers grounded in an LLM-first search engine and our specialized data sources. We aim to use the latest models as they are released, but the intelligence frontier is a jagged one, and popular benchmarks do not effectively cover our use cases. In this role, you will build specialized evals to improve answer quality across Perplexity, covering search-based LLM answers and other scenarios popular with our users.

Responsibilities

  • Architect and maintain automated evaluation pipelines to assess answer quality across Perplexity's products, ensuring high standards for accuracy and helpfulness

  • Design evaluation sets and methods specifically to measure the impact of tool calls (particularly web search retrieval) on the final answer's quality

  • Develop VLM-based solutions to programmatically evaluate how final answers render visually across different platforms and devices

  • Continuously review public benchmarks and academic evaluations for their applicability to the Perplexity product, adapting and incorporating them into our regular performance measurements

  • Operate within a small, high-impact team where your evaluation metrics directly shape product changes, collaborating closely with technical leadership to measure and improve Answer Quality

Qualifications

  • PhD or MS in a technical field or equivalent experience

  • 4+ years of experience in data science or machine learning

  • Strong proficiency in Python and SQL (expected to write production-grade code)

  • Experience building within a modern cloud data stack, specifically AWS and Databricks

  • Comfortable with agentic coding workflows and using AI-assisted development tools to iterate faster

Preferred Qualifications

  • 1+ years of experience working with LLMs at scale, specifically with LLM-as-a-judge setups

  • Prior experience working on customer-facing web products or consumer apps, with real user traffic at scale

  • A strong research background, with experience applying research methods to real-world ML problems

  • Experience defining evaluation metrics (e.g., factual consistency, hallucination rate, retrieval precision) and building ground truth datasets

Salary Range: $200K - $300K

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