1. Home
  2. Jobs
  3. United Kingdom
  4. London
  5. AI
  6. Data Scientist, Evals
PE

Data Scientist, Evals

Perplexity
Posted onFeb 17, 2026
LocationLondon, England, United Kingdom | Belgrade, Belgrade, Serbia | San Francisco, California, United States | Berlin, Berlin, Germany (On-site)
Employment typeFull-time
Salary$210k – $385k Yearly

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: $210K – $385K • Offers Equity

Perplexity is an AI-powered answer engine that provides accurate, real-time answers to questions backed by credible sources and citations.

Similar jobs

You might also be interested in...

CO1w

Member of Technical Staff, Pretraining evaluations

Cohere

London, England, United Kingdom or Remote (Worldwide)

SC5d

Senior Forward Deployed Data Scientist/Engineer

Scale

San Francisco, California, United States (Hybrid)

$198k – $247.5k Yearly

OP1w

Data Scientist, Codex

OpenAI

San Francisco, California, United States (Hybrid)

$255k – $405k Yearly

CR2d

AI Intern, Digital Infrastructure Group, Summer 2026

Crusoe

San Francisco, California, United States (On-site)

From $87.9k Weekly

SC1w

Machine Learning Engineer - Model Evaluations, Public Sector

Scale

San Francisco, California, United States (On-site)

$216.3k – $300.3k Yearly