I work on cobol migrations (or anything mainframe more correctly) to x86. I've never seen a rewrite of a real application that actually worked. Some have tried

I work on cobol migrations (or anything mainframe more correctly) to x86. I've never seen a rewrite of a real application that actually worked. Some have tried but ended up throwing the towel. We've taken a different approach, by being binary compatible. Basically we rewrote a CICS/IMS/etc, as well as some z/OS layers. Depending on the clients, some want to stay in cobol, but others want to modernize, but in a controlled and progressive way. A complete rewrite is out of the question, but you can try to do it in steps.