STEM PhD Researcher for AI Model Evaluation

Join a leading AI lab''s cutting-edge research team to be at the core of the AI revolution, where your expertise fuels the development of the most advanced LLMs. Overview

Advanced STEM Researchers and PhD-level subject-matter experts (SMEs) are needed to contribute to a project supporting a frontier-model evaluation effort focused on rigorous scientific and technical reasoning. The AI lab is building next-generation models capable of solving complex, research-grade problems across the sciences and requires deep domain expertise to design, solve, and evaluate the challenging tasks that train and benchmark these systems.

This is a W-2 employment position with Cincinnatus LLC, requiring a commitment of 40 hours per week during weekdays. This position will be placed at a leading AI Lab as part of their extended workforce.

• Guide research teams to close knowledge gaps in STEM domains by surfacing edge cases, ambiguities, and frontier problems where current models underperform.
• Design challenging, rigorous domain tasks and write accurate, well-reasoned solutions that demonstrate expert-level scientific and technical reasoning.
• Evaluate tasks and solutions produced by AI agents and other contributors, providing clear written technical feedback grounded in domain expertise.
• Develop evaluation frameworks and rubrics for assessing scientific reasoning quality across STEM domains.
• Collaborate with other subject matter experts to ensure consistency and accuracy in training data.

• PhD (completed, enrolled, or equivalent research track) in Physics, Chemistry, Biology, Mathematics, Statistics, Computer Science, Electrical Engineering, Mechanical Engineering, Civil Engineering, Materials Science, or another STEM discipline.
• 3+ years of research, academic, or industry experience in their primary STEM domain.
• Demonstrated technical expertise in at least one domain: computational modeling, laboratory methods, data analysis, statistical inference, programming, or equivalent scientific methods.
• Ability to commit to 40 hours per week during weekdays for the duration of the engagement.
• Prior experience with data annotation, labeling, evaluation, or human feedback collection is a strong plus.
• Experience with LLMs, AI systems, or agentic workflows; familiarity with agentic frameworks is a plus.
• Strong written communication skills; ability to explain complex scientific or technical concepts clearly in writing.

Cincinnatus LLC is an enterprise staffing company that partners with leading technology companies to source and employ highly skilled professionals for contingent and contract-based opportunities. Cincinnatus serves as the employer of record for these engagements, providing W-2 employment, payroll, benefits, and compliance, while placing employees directly within client teams to work on high-impact initiatives.

Cincinnatus is proud to be an Equal Employment Opportunity employer. We do not discriminate based upon race, religion, color, national origin, sex (including pregnancy, childbirth, reproductive health decisions, or related medical conditions), sexual orientation, gender identity, gender expression, age, status as a protected veteran, status as an individual with a disability, genetic information, political views or activity, or any other legally protected characteristic.