Member of Technical Staff - Data Quality Engineer (Post-training)
Reflection AI · San Francisco, CA · London · New York, NY
CHECKED 19H AGO
Frontier labonsite
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