Software Engineer (Foundational)

Join a leading AI lab's cutting-edge GenAI team to be at the core of the AI revolution, where your expertise fuels the development of the most advanced Large Language Models.

1. Overview

Join a leading AI lab's cutting-edge GenAI team and help build foundational AI models from the ground up. We're seeking talented Software Engineers with hands-on expertise in production software engineering across Python and at least one systems or backend language (Java, C++, Go or Rust) to bring rigorous engineering judgment and elevate the quality of our AI training data.

This is a W-2 employment position with Cincinnatus LLC, with the opportunity to be placed at a leading AI Lab as part of their extended workforce.

2. Key Responsibilities

• Guide research and engineering teams to close knowledge gaps and improve AI model performance in software engineering, algorithms and data structures, and backend and systems design topics.
• Design challenging, domain-relevant tasks, and write accurate and well-structured solutions to software engineering problems.
• Evaluate software engineering tasks and solutions and provide clear, written technical feedback.
• Write, review and debug realistic multi-file coding tasks, including unit tests and reference solutions that run cleanly.
• Develop rubrics to assess code correctness, readability, test coverage and design tradeoffs in model-generated code.
• Collaborate with other subject matter experts to ensure consistency and accuracy in training data.

3. Core Qualifications

• 4+ years of dedicated professional software engineering experience at a recognized, top-tier technology company or high-growth startup.
• Strong production proficiency in Python plus at least one of Java, C++, Go or Rust.
• Hands-on experience with Git workflows, code review, automated testing and CI.
• Demonstrable career progression (e.g., Software Engineer → Senior Engineer → Staff or Tech Lead).
• Ability to engage reliably for at least 20 hours/week during weekdays.
• Strong written communication skills and the ability to explain complex technical decisions clearly.

About Cincinnatus LLC: 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.

Equal Employment Opportunity: 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.