COBOL Code Reading / Writing Expert

We are looking for experienced COBOL developers who can read, understand, debug, and write production-quality COBOL code. You will work on tasks that help train and evaluate AI models on legacy software engineering workflows, especially mainframe-style codebases.

Responsibilities

• Read and interpret COBOL programs, copybooks, JCL, and related mainframe code.

• Write clean, correct COBOL code based on technical requirements.

• Debug COBOL logic and identify issues in existing programs.

• Explain code behavior, business logic, and data flow clearly.

• Review AI-generated COBOL solutions for correctness, completeness, and style.

• Create or evaluate test cases for COBOL programs.

• Provide high-quality feedback to improve AI model performance on legacy code tasks.

Requirements

• Strong hands-on experience with COBOL development.

• Ability to read and write COBOL code independently.

• Familiarity with mainframe environments such as IBM z/OS is preferred.

• Experience with JCL, VSAM, DB2, CICS, or copybooks is a plus.

• Strong debugging and code review skills.

• Clear written communication in English.

• Prior experience in banking, insurance, government, or enterprise legacy systems is a plus.

Ideal Candidate

• Has worked on real-world COBOL systems, not just academic examples.

• Can explain legacy code clearly to both technical and non-technical audiences.

• Is comfortable evaluating code quality and reasoning through edge cases.

• Has experience maintaining or modernising large legacy codebases.

Why Join

• Contribute to cutting-edge AI systems focused on software engineering.

• Help models better understand and support legacy enterprise code.

• Work on intellectually engaging code evaluation and generation tasks.

• Flexible opportunity for experienced COBOL engineers.

We consider all qualified applicants without regard to legally protected characteristics and provide reasonable accommodations upon request.

Contract and Payment Terms

• You will be engaged as an independent contractor.
• This is a fully remote role that can be completed on your own schedule.
• Projects can be extended, shortened, or concluded early depending on needs and performance.
• Your work at Mercor will not involve access to confidential or proprietary information from any employer, client, or institution.
• Payments are weekly on Stripe or Wise based on services rendered.
• Please note: We are unable to support H1-B or STEM OPT candidates at this time.

About Mercor

Mercor partners with leading AI labs and enterprises to train frontier models using human expertise. You will work on projects that focus on training and enhancing AI systems. You will be paid competitively, collaborate with leading researchers, and help shape the next generation of AI systems in your area of expertise.