1. Proficiency in COBOL programming (COBOL-85, COBOL II, or later versions)
2. Experience working with mainframe environments (IBM z/OS, OS/390, or similar)
3. Robust knowledge of JCL (Job Control Language) and other mainframe utilities
4. Familiarity with databases commonly used with COBOL systems, such as IMS DB, GSAM, DB2, or VSAM