Skip the Lift-and-Shift: Why Replatforming Is the Cheapest Way to Cloud

There's a persistent myth in cloud migration: that the cheapest way to get to the cloud is to lift and shift everything. It feels right—no code changes, no rework, just pick up your servers and drop them into a virtual machine. But I've seen too many teams discover too late that a rehosted workload is a cost bomb waiting to explode. The truth is, a targeted replatforming—what AWS calls "lift, tinker, and shift"—is often the cheapest path, and here's why.

The Myth of Cheap Rehosting

Rehosting is fast. It's simple. It doesn't require touching a single line of code. But it also leaves you with a cloud environment that's basically your old data center, just rented by the hour. The Flexera 2025 State of the Cloud report found that 84% of organizations struggle to manage cloud spend—and that's not an accident. When you rehost, you carry over all the inefficiencies of your on-premises setup: over-provisioned CPUs, idle databases, and applications that were never designed to scale horizontally. You end up paying cloud prices for on-premises behavior.

Worse, rehosting doesn't give you any of the native cloud cost levers. You can't easily scale down a monolithic app that was built for a fixed server. You're stuck paying for a reserved instance that's either too big or too small, and you're constantly fighting to keep utilization reasonable. The Red Hat survey confirms that only 38% of organizations plan to start with rehosting, and then move to replatforming or refactoring later—but by then, you've already paid the migration tax twice.

What Replatforming Actually Does (and Why It's Cheaper)

Replatforming is the middle path. You keep the core architecture of your application, but you make small, targeted changes to take advantage of cloud-managed services. For example, instead of running your own SQL Server on a VM, you move to Amazon RDS for SQL Server. Instead of managing your own load balancer, you use the cloud's managed version. These are not architectural rewrites—they're operational swaps. And they directly cut your cost per workload.

The numbers back this up. In a Red Hat survey, replatforming was the most common migration approach at 20%—and that's because it hits the sweet spot between effort and savings. You don't need to break your app into microservices (that's refactoring, and it's the most complex and costly strategy, according to AWS). You just need to modernize the bits that are easiest to modernize, and let the cloud provider handle the rest.

A Field Report: The 80-System Consolidation

Imagine you're the IT director at a mid-sized manufacturing company. You have 80 SAP systems running on aging on-premises servers, and your CFO is demanding a cloud migration that doesn't blow the budget. You've heard the horror stories of rehosting—the surprise egress fees, the idle capacity, the lack of elasticity. So what do you do?

You decide to replatform, not rehost. You move your SAP workloads to a cloud provider's managed database service, and you consolidate those 80 systems into a single, cloud-native architecture. AWS has a documented case study of exactly this: a customer consolidated 80 SAP systems and achieved 30% cost savings through a cloud-native transformation. That's not a typo—30%. And they did it without a full refactor. They just stopped paying for 80 separate instances of everything and started paying for one well-utilized, managed environment.

That's the power of replatforming. You're not rewriting your business logic; you're changing the infrastructure underneath it. And because you're using managed services, the cloud provider handles the patching, the scaling, and the backups—which means you also save on operational overhead, not just raw compute.

Comparing the Strategies: Cost, Speed, and Risk

To see the trade-offs clearly, let's put the three main strategies side by side.

As you can see, rehosting is the cheapest to start but leaves money on the table. Refactoring is the most transformative but is so expensive that AWS explicitly advises against it for large migrations—they recommend rehost, replatform, relocate, and retire instead. Replatforming is the Goldilocks option: you get a meaningful cost reduction without the risk of a rewrite.

How to Replatform Without Losing Your Mind

So how do you actually replatform successfully? The key is to use a phased approach, like the Azure migration framework: Assess, Migrate, Optimize, and Monitor. Start with a thorough assessment using a tool like Azure Migrate, which is free and can discover your entire on-premises estate, including dependencies. This is critical because a common pitfall is missing dependencies, which leads to broken applications and budget overruns.

Then, during the migrate phase, don't try to replatform everything at once. Pick a few high-value workloads—like that SQL Server database or that legacy web app—and do a pilot. Use the cloud provider's tools to automate the migration as much as possible, and don't forget to right-size your instances based on actual performance data, not just your old on-premises specs.

Finally, enter the optimize phase. This is where you really capture savings. Turn off idle resources, use reserved instances for steady-state workloads, and take advantage of serverless options where it makes sense. As Red Hat points out, an idle serverless function costs nothing—that's a cost model you simply can't get with a rehosted VM.

And don't forget the FinOps piece. Flexera's 2026 data shows that 63% of organizations now have a dedicated FinOps team, and 71% have a Cloud Center of Excellence. You need someone watching the spend, because cloud cost optimization isn't a one-time event—it's a continuous discipline. The Flexera 2025 report found that 87% of organizations say cost efficiency is their number one metric for assessing cloud goals, yet wasted cloud spend on IaaS and PaaS rose to 29% in 2026, the first increase in five years. That's a warning: if you don't actively manage it, costs will creep back up.

Sources

• DigitalOcean - https://www.digitalocean.com/resources/articles/cloud-migration-strategy
• Red Hat - https://www.redhat.com/en/blog/how-should-you-modernize-your-applications
• AWS Prescriptive Guidance - https://docs.aws.amazon.com/prescriptive-guidance/latest/large-migration-guide/migration-strategies.html
• Flexera 2025 - https://www.flexera.com/about-us/press-center/new-flexera-report-finds-84-percent-of-organizations-struggle-to-manage-cloud-spend
• Flexera 2026 - https://www.flexera.com/blog/finops/the-new-era-of-cloud-what-2026-data-tells-us-about-spend-scale-and-strategy/
• Azure Migrate - https://learn.microsoft.com/en-us/azure/migrate/migrate-services-overview