Research Scientist - Post Training

Why Apply

Massive Opportunity: Forbes reported that we could be YC's fastest unicorn, reportedly raising at a $3.2 billion valuation, and we're not slowing down.

Founding Impact: You will own and architect core infrastructure systems that power our platform from the ground up.

Equity & Growth: Competitive salary and meaningful equity. As we scale, you’ll have the opportunity to shape the engineering organization and lead major technical initiatives.

Strong Team: Our founding team has experience from Citadel Securities, Meta, Google, Silver Lake, and Morgan Stanley - work alongside world-class engineers and researchers.

Overview

Your job is to prove that our data works. You will design and run training experiments that isolate the impact of our datasets on model behavior. This includes SFT and RL-based post-training, where you’ll measure how different data sources shift capability, generalization, and alignment. Working closely with partner labs, you will turn our datasets into clear, defensible evidence: this data > this improvement > under these conditions. This is experimental, high-leverage work.

Responsibilities

• Run controlled SFT and RL experiments to measure the impact of our datasets on model performance.
• Help build public evals and new data types that push the frontier.
• Publish external-facing research, blog posts, and technical reports.
• Work with internal SPLs to iterate on data quality based on your results.

Required Qualifications

• Strong familiarity with LLM training and evaluation methodologies.
• Ability to design lightweight experiments, move fast, and extract actionable insights from messy results.
• Comfort working across domains (you'll touch finance, software engineering, policy, and more).
• A bias toward building over theorizing.

Preferred Qualifications

• Great candidates are undergrad research or master's research (but haven't done a phd).
• Genuine obsession with how data structure, selection, and quality drive model behavior.

Company Benefits (For Eligible Employees)

• Health Insurance: Medical, Vision, Dental
• 401(k) with Employer Match
• Daily Meals: Daily UberEats Stipend
• Monthly Wellness Stipend

We comply with applicable pay transparency requirements and provide compensation ranges based on the position, qualifications, experience, and other relevant factors. This job description is intended to describe the general nature and level of work performed and is not an exhaustive list of all duties, responsibilities, qualifications, or working conditions associated with the position. We reserve the right to modify this job description as business needs change.