I worked at a large health insurance company a few years back. They had a DB2 server running on an IBM mainframe that they were working on replacing with a data

I worked at a large health insurance company a few years back. They had a DB2 server running on an IBM mainframe that they were working on replacing with a data lake and cloud-based NOSQL solutions. It seemed rather pointless to me. The DB2 server was serving queries just fine and when we were working on setting up a microservice that would allow viewing claims history, the storage and server costs for being able to provide queries against three years’s claims were prohibitive. But they were still persisting down that road when I left.