Cloud Migration Patterns That Actually Work
Lift-and-shift is not the only option, and it is rarely the best one. A field guide to the five migration patterns and when to use each.
Every cloud migration starts with the same question: how much do we change on the way? Move too little and you carry your old problems into a more expensive environment. Move too much and the project stalls under its own weight.
The five patterns
The industry commonly describes five migration patterns, sometimes called the five Rs. Rehost means moving an application as-is. Replatform means making a few cloud optimizations without changing the core architecture. Refactor means rearchitecting for cloud-native services. Repurchase means replacing the application with a SaaS product. Retire means switching it off because nobody actually needs it.
Match the pattern to the workload
A legacy system with a looming datacenter contract deadline is a candidate for rehosting. You get out of the datacenter quickly, then optimize later. A revenue-critical application that struggles to scale is worth refactoring, because the cloud-native payoff justifies the effort. A commodity workload like email is usually best repurchased.
Do not skip the discovery phase
The most expensive migration mistakes are made before anyone touches the cloud. Underestimating data transfer costs, missing hidden dependencies, and ignoring compliance boundaries all surface late and hurt. A thorough discovery phase, mapping every dependency and data flow, is the cheapest insurance you can buy.
Optimize after you land
Migration is not the finish line. Right-sizing instances, adopting managed services, and introducing autoscaling typically cut cloud bills by a third or more in the first six months. Plan for a post-migration optimization phase and budget the time to do it properly.
