Member of Technical Staff (Search Crawler Analyst)

Perplexity; Greater London; On-site; GBP 65,000 - 90,000; Full time

Job summary

Perplexity is building a scalable crawling and indexing platform. We are seeking a data analyst/ML engineer to design metrics, build data pipelines, and improve search quality.

You will diagnose quality issues in the crawling pipeline, train small models for parsing quality, and design experiments to validate improvements, collaborating across data and engineering teams.

Qualifications

• 4+ years of experience as a data analyst, ML engineer, or related role.
• Ability to write production-grade code at the level of a mid-level backend engineer.
• Experience designing metrics from scratch.
• Experience training ML models that shipped to production with measurable metric improvements.

Responsibilities

• Find and diagnose quality issues in crawling pipeline.
• Train small models that optimize parsing quality.
• Build datasets for model training, including labeling pipelines.
• Improve page selection algorithms for indexing.
• Design and analyze experiments to validate improvements.

Skills

Coding skills

Metrics design

Data analysis

ML understanding

Tools

Python

Backend development

Job description

The internet is vast, containing trillions of URLs. Perplexity’s crawling and storage system is complex and has multiple stages (URL discovery, crawling, parsing, indexing). Each stage offers many opportunities for improvement and room for intricate bugs. You’ll work at the intersection of data analysis and engineering — designing metrics, building data pipelines, and improving the quality of our search and answer systems.

Responsibilities

• Find and diagnose quality issues in our crawling pipeline
• Train small models that optimize particular aspects of the pipeline (e.g. parsing quality)
• Build datasets for model training, including LLM-as-a-judge labeling pipelines
• Improve page selection algorithms for indexing
• Design and analyze experiments to validate improvements

Qualifications

• 4+ years of experience as a data analyst, ML engineer, or in a related role
• Strong coding skills: you should be able to write production-grade code at the level of a mid-level backend engineer
• Experience designing metrics from scratch
• Experience training ML models that shipped to production with measurable metric improvements

Nice to have

• Direct experience working on web crawling or indexing pipelines