Software Engineer (Trajectory)

Mercor is hiring experienced Software Engineers
to support high-impact research collaborations with leading AI labs. Freelancers will contribute to building training datasets that improve AI model reasoning and problem-solving on real-world coding tasks.
This is a unique opportunity to apply your software engineering expertise toward shaping the next generation of intelligent systems.
About The Project
You'll annotate frontier-model trajectories on
SWE-bench–style tasks
derived from real open-source repositories. Currently, closed-source models do not expose their internal reasoning traces, making it difficult to understand how LLMs approach problem-solving.
To address this gap, you'll
reconstruct and annotate the reasoning portions
of model trajectories—using your own problem-solving process and the full task context to infer and infill the underlying thought process at each step.
Key Responsibilities

• Review model-generated code trajectories on realistic software engineering tasks
• Reconstruct chain-of-thought reasoning that explains each step of the solution process
• Annotate decision points, debugging logic, and problem-solving strategies
• Use full task context (codebase, issue descriptions, test cases) to infer plausible reasoning
• Ensure annotations reflect realistic developer thought processes and technical accuracy

Ideal Qualifications

• 2+ years of experience in software engineering, with hands-on debugging and problem-solving in real codebases
• Degree in Software Engineering, Computer Science, or a related field (Bachelor's minimum; advanced degree preferred)
• Strong proficiency in Python, JavaScript, TypeScript, or other common languages found in open-source projects
• Familiarity with version control workflows (Git, PRs, issue tracking)
• Comfortable articulating technical reasoning in clear, structured writing

Project Timeline

• Start Date: Immediate
• Duration: 1–2 months
• Commitment: Part-time (15–25 hours/week, with flexibility up to 40 hours/week)

Application & Onboarding Process

• Upload your resume
• AI interview: A short, 15-minute conversational session to understand your background, experience, and interest in the role
• Follow-up communication within a few days with next steps and onboarding details

Apply today
and leverage your software engineering expertise to help build the future of AI-driven systems!