If you're looking for a mainframe refresher, here are some general topics and resources that might be helpful:

: Essential modules on File-Aid , Endevor , and Changeman .

: Language history, structure (divisions/sections), coding standards, and advanced concepts like the OCCURS clause.

Many developers maintain "Interview Prep" repos that include this PDF as a standard reference for legacy systems.

Mainframe systems continue to power the backbone of global finance, insurance, and retail. Despite the rise of cloud computing, the demand for skilled mainframe professionals remains high. Muthu’s guide gained popularity because it distills thousands of pages of IBM documentation into high-impact "cheat sheets" and interview-ready Q&A formats. Core Modules Covered