One of my most recent projects involved helping a client move many decades of code from a mainframe environment to a distributed Java web environment. The client had engaged another company to actually transform the mainframe code to Java, and our team was tasked with making it all actually work.

One of the major areas we had to deal with was the transition of all of the batch processes. Of course, Spring Batch came to our rescue for most of the work, and was an easy choice as we were already using Spring Boot to wrapper the converted applications.

The most challenging part of the entire project was that the client did not want to move everything at once in a Big Bang, but rather a few programs as a time. This meant that some programs would be running in the Java environment while others remained on the mainframe.

In this blog, I discuss three data challenges we encountered in the transition of an enterprise mainframe to Java web application with Spring Batch, how we overcame them, and tips to keep in mind going forward when in similar migration situations.