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Member of Technical Staff - Data Quality Engineer (Post-training)

Reflection AI · San Francisco, CA · London · New York, NY

CHECKED 19H AGO

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At a glance

Highlights

  • Own data quality for LLM post-training shaping agentic tool use and reasoning.
  • Build scalable QA pipelines and LLM-as-a-Judge to measure quality at scale.
  • Turn fuzzy notions of good data into measurable standards for model training.

What they offer

  • Top-tier salary and equity with stock options
  • Comprehensive medical, dental, vision, life coverage plus wellness allowance
  • Lunch and dinner provided in office daily
  • 22 weeks paid parental leave
  • Unlimited PTO in U.S. and 30 days in U.K.
  • Visa sponsorship and immigration support
  • Regular off-sites, happy hours and team celebrations

Ideal candidate

Detail-oriented engineer fascinated by how data quality shapes model behavior, who thrives owning ambiguous problems end-to-end and partnering with researchers to turn quality insights into better models.

Requirements

  • Experience building data pipelines, QA systems, or evaluation workflows for post-training data
  • Detail-oriented and analytical, able to spot failure modes and subtle data issues
  • Understanding of how data quality impacts SFT, RL training and evaluation
  • Experience designing and validating automated quality checks including LLM-as-a-Judge
  • Comfortable owning problems end-to-end and collaborating with researchers and operations
  • Proficiency in Python and building ML/LLM workflows
  • Experience with large datasets and automated evaluation systems
  • Familiarity with how LLMs are trained and evaluated
  • Excellent communication skills across teams
visa sponsorship
Visa sponsorship available

Lab profile

About Reflection AI

Research lab making intelligence open and accessible for everyone to use, customize, and build on.

What they build

  • Open foundation models
  • Aligned general agents
  • Enterprise AI deployments

Known for

  • Frontier model pre-training
  • Post-training and alignment
  • Distributed training infrastructure
  • Secure cloud platform foundations
More about Reflection AI →
Apply on the lab’s site ↗