This job post has expired on June 05, 2026. It is likely that the position has already been filled.
COBOL Developer & Code Expert at Mercor
posted 5 months agoCOBOL Developer & Code Expert | $80–100/hr | Worldwide Remote
Mercor is seeking experienced COBOL developers to read, write, debug, and evaluate production-quality COBOL code. In this role, you will directly contribute to training and improving AI models on legacy software engineering workflows, with a focus on mainframe-style codebases. This is a flexible contractor opportunity ideal for seasoned COBOL engineers looking to apply their expertise in a cutting-edge AI context.
Responsibilities
- Read and interpret COBOL programs, copybooks, JCL, and related mainframe code.
- Write clean, correct COBOL code based on provided technical requirements.
- Debug COBOL logic and identify issues within existing programs.
- Clearly explain code behavior, business logic, and data flow to varied audiences.
- Review AI-generated COBOL solutions for correctness, completeness, and coding style.
- Create and evaluate test cases for COBOL programs.
- Provide high-quality, structured feedback to improve AI model performance on legacy code tasks.
Requirements
- Strong hands-on experience with COBOL development in real-world environments.
- Ability to independently read and write COBOL code to production standards.
- Familiarity with mainframe environments such as IBM z/OS (preferred).
- Experience with JCL, VSAM, DB2, CICS, or copybooks is a plus.
- Strong debugging and code review capabilities.
- Clear written communication skills in English.
- Background in banking, insurance, government, or enterprise legacy systems is advantageous.
Ideal Candidate
- Has worked on real-world COBOL systems beyond academic or training examples.
- Can explain legacy code clearly to both technical and non-technical stakeholders.
- Is comfortable evaluating code quality and reasoning through edge cases.
- Has experience maintaining or modernizing large-scale legacy codebases.
Why Join
- Contribute to cutting-edge AI systems focused on software engineering.
- Help AI models better understand and support legacy enterprise code.
- Engage in intellectually stimulating code evaluation and generation tasks.
- Enjoy a flexible, remote contractor arrangement suited to experienced engineers.
How to apply for this role
- Upload your resume — keep it up-to-date and in English. Mercor will auto-fill your profile from it.
- Complete the AI interview — a 15-minute conversation about your experience. Be ready to discuss specific projects and challenges you've solved.
- Submit your application — only about 20% of applicants finish all the steps, so completing yours puts you well ahead.