Senior Python Engineer for Codebase Reasoning & AI Tasks

Obsidian; San Francisco (CA); Remote; USD 1,100 - 2,200; Full time

Job summary

Mercor is seeking experienced Python engineers to build datasets that teach AI agents to reason about real codebases. You will select tasks from a pool of Python repositories, reproduce and understand subsystem behavior, and craft challenging questions and rubrics.

This is a fully remote, asynchronous role with expert team leads across multiple time zones. Tasks are paid per approved submission at $130, with documentation and expert review steps required before acceptance.

Qualifications

• 3+ years of professional software engineering experience with production Python.
• Ability to navigate large, unfamiliar Python codebases and explain runtime behavior.
• Fluency in Python internals: import machinery, descriptors/metaclasses, async/event loops, packaging, C extensions.
• Experience with web frameworks, tooling, type checkers, or scientific/numeric libraries is valuable.
• Precise written English for crafting questions and rubrics.
• Comfortable with git at commit level, containerized environments, and CLI tooling.

Responsibilities

• Select tasks from a pre-validated pool of Python repositories, each pinned to a specific git commit and arriving with an engineering question, positive and negative rubrics, foils, and a golden solution
• Explore the repository until you genuinely understand the subsystem in question, including the relevant PR or issue history
• Rewrite the task's question so it defeats frontier coding agents while remaining well-defined and fairly answerable
• Adjust rubrics and foils so they reward correct reasoning and reject plausible-but-wrong answers
• Run the full validation loop in Studio — Check, Golden, Run, Analyze — and iterate until every stage passes
• Document your work in the task README and submit for expert review, addressing reviewer feedback on returned tasks

Skills

Python

3+ years experience

Codebase navigation

Async programming

Git

Containerization

Command-line tooling

English proficiency

Tools

Git

Containerization

Command-line

Job description

Mercor is seeking experienced Python engineers to build datasets that teach AI agents to reason about real codebases. You will select tasks from a pool of Python repositories, reproduce and understand subsystem behavior, and craft challenging questions and rubrics.

This is a fully remote, asynchronous role with expert team leads across multiple time zones. Tasks are paid per approved submission at $130, with documentation and expert review steps required before acceptance.