It’s Monday morning. You go into work as if it’s a normal day, but the office is quiet. There’s a press release on your desk stating that your company has put its datacenters up for sale, and cloud will be its new platform.

This strategic shift is increasingly commonplace now. Although it makes the company look innovative and thrifty to the stock holders, it also leaves the challenge to IT to make it all work.

The shift to the cloud is very sensible. Most applications have a place on the public cloud—that is, if they are modern enough to use the public cloud as a platform. Indeed, in some cases the application workloads don’t have to be modified or need very little modification. Migrating to the cloud often makes sense.

But often is not always. Some applications—about 20 to 40 percent—don’t have good platform analogs in public cloud platforms. Most are built using older mainframe or minicomputer technologies; although they’re not pretty to look at, they run the business nonetheless. Modifying those applications to run in the cloud is cost-prohibitive.