IBM i in the Hybrid Cloud Era: A Practical Roadmap for AS400 Modernization and Migration Success

Ask 10 IBM i organizations why they haven’t moved to the cloud, and at least seven will say iterate “it just works.” This is not wrong, but it is also not the whole picture anymore.

Digital transformation has stopped being a differentiator and become table stakes. For organizations running mission-critical ERPs, inventory systems, or financial workloads on AS400/IBM i, that shift raises an uncomfortable question: how do you modernize without touching the one system nobody wants to break?

The answer most are landing on is not rip-and-replace. It is hybrid cloud, bolting cloud-native flexibility onto a platform that has never needed convincing about reliability. This is not a theoretical debate anymore. It shows up in the numbers, which will be covered in the blog ahead.

This guide explores why hybrid cloud migration has become a strategic priority for IBM i organizations, the most common challenges enterprises encounter, and the best practices that pave the way for a successful, future-ready cloud transformation.

What Is Pulling IBM i Organizations Toward the Cloud?

Here is where the picture gets interesting, and a little contradictory.

Fortra’s 2026 IBM i Marketplace Survey found that 77% of organizations still plan to run their IBM i workloads entirely on-premises¹. That’s not a shrinking number. In fact, it shows that IBM i loyalty runs deep, and for good reason.

Organizations relying solely on a cloud or managed service provider hit a record high of 13% this year, overtaking hybrid as a standalone deployment category for the first time¹. The analysts note the real cloud footprint is probably even larger than reported, since many organizations run their disaster recovery instances in the cloud without labeling the whole environment “hybrid.”

So, which is it: loyalty to on-premises, or a quiet migration underway? Both, really. And that’s the point. IBM i is not abandoned. It is being repositioned as the dependable core of something larger. Think of it less as a platform in decline and more as a foundation that’s finally getting the extension it needs, one that lets newer, more elastic systems plug in around it without disturbing what already works.

That distinction matters for how leadership teams frame this internally. Casting hybrid cloud as an “IBM i replacement strategy” tends to trigger resistance from teams who’ve spent years keeping these systems running without drama. Framing it instead as an extension of that same reliability just with more flexible edges tends to get buy-in a lot faster.

Three forces explain the pull:

i. Cost Is No Longer a Footnote

Aging AS400 hardware means absorbing upgrade cycles, licensing renewals, and facility overhead that scale badly as a business grows. Cloud’s pay-as-you-go model flips that math, as you pay for what you use, not what you might need someday.

ii. The Talent Pipeline Is Thinning

IBM i skills shortages consistently rank among the top concerns IT leaders report year over year. Offloading patch management, PTF work, and hardware refreshes to a cloud or managed provider takes that burden off an already-stretched team.

iii. Flexibility Matters More Than It Used To

A workload untethered from physical hardware adapts faster to demand spikes, to new integrations, to whatever comes next. On-premises systems weren’t built for that kind of elasticity, and retrofitting them only goes so far.

None of this is abstract strategy. Rehosting remains the fastest, lowest-risk way to act. It is the process of migrating applications with minimal code changes, often called “lift and shift.” Major providers, Microsoft Azure among them, have built migration roadmaps specifically around this approach for IBM i workloads.

The decision to adopt hybrid cloud is only the first milestone. Successful IBM i modernization depends on whether the organization has the technical, operational, and governance foundations needed to support the transition. Before planning the migration, use this quick readiness scorecard to assess where your organization stands.

If your organization checks most of these readiness criteria, the next question is not whether to migrate, but where to begin. A structured assessment of applications, workloads, dependencies, and business priorities helps establish the right migration sequence while minimizing operational risk.

Where Should an AS400 Migration Really Begin?

Every migration that goes sideways shares one thing in common: someone skipped the inventory.

Before a single workload moves, IBM i teams need a genuinely honest look at what they’re running, i.e., applications, workloads, databases, and how tightly they’re all wired together. Not a surface-level list. A real assessment of resource demands, dependencies, and performance baselines. This is what separates a workload that’s cloud-ready from one that will break the moment it leaves familiar hardware.

From there, prioritization comes down to a blunt question: what can afford to go wrong first? Test environments, reporting tools, and archival systems make natural starting points. This is because these are low-stakes, useful for building confidence, and catching surprises before anything customer-facing is on the line.

Write the plan down. Document what moves, in what sequence, and under which model, such as rehosting, refactoring, or re-platforming. This is not bureaucracy for its own sake. It is what keeps a six-month migration from becoming an eighteen-month one, and it gives stakeholders outside IT something concrete to hold onto.

It also does something less obvious but equally important: it forces early conversations about ownership. Who signs off when a workload is deemed cloud-ready? Who decides if a delay is acceptable? Migrations that stall midway often trace back not to technical failure but to nobody having answered these questions before the project started. A written plan, shared across IT and business stakeholders, closes that gap before it becomes a bottleneck.

Once the groundwork is set, the next decision is where all that planning lands.

Which Cloud Model and Which Migration Path Fits Your Business?

Public cloud brings flexibility and consumption-based pricing, but it raises fair questions about vendor lock-in, data residency, and regulatory exposure. Private cloud tightens control and security, at the cost of higher upfront spend and ongoing upkeep. Hybrid splits the difference: sensitive or latency-bound workloads stay close, while everything else borrows cloud-native scale and reach.

The right answer is not universal. It depends on:

• Data sovereignty obligations
• Budget reality
• Workload behavior
• Regulatory environment

Get this wrong early, and re-architecting later gets expensive fast.

A Side-to-Side Comparison of Different Cloud Models

A useful way to think about it: treat the decision workload by workload rather than as one company-wide verdict. A financial reporting system with strict residency requirements might belong on private infrastructure, while a customer-facing analytics dashboard could run comfortably on public cloud with no compliance friction at all. Hybrid cloud, done well, is a portfolio of decisions, each matched to what that particular workload actually needs.

Migration approach follows the same logic:

• Rehosting is quickest and suits applications with few tangled dependencies.
• Refactoring or re-platforming take longer, but they’re worth it for workloads that need to shed legacy baggage permanently rather than just relocate it.

Whichever path fits, test in stages: a contained pilot first, full cutover later. Spotting a compatibility problem in a small pilot costs little but getting it after go-live costs a lot more, and usually at the worst possible time.

With the model chosen and a path mapped out, there is still the question of whether the applications themselves are ready to make the move.

Does Migrating Mean Rewriting Everything Organizations Own?

Not necessarily, but “lift and shift” rarely tells the whole story either.

Plenty of IBM i applications were built for a physical, tightly-coupled world, and moving them as-is can surface friction nobody planned for: dependencies on software versions the cloud doesn’t support, monolithic designs that resist scaling, integrations that behave differently once decoupled from familiar hardware.

Modernizing for the cloud usually means breaking monolithic applications into more modular components, updating software versions for compatibility, and occasionally rearchitecting pieces for serverless execution. It also means mapping external integrations and legacy dependencies ahead of time, so nothing quietly breaks mid-migration. The payoff is not just an application that’s cloud-hosted; it is one that behaves like it belongs there, scaling and updating without the friction that plagues a rushed lift-and-shift.

Consider a typical order-processing application built decades ago as a single, tightly wired program. Moved as-is, it might technically run in the cloud, but it will scale as a single unit, meaning a spike in order volume forces the entire application to scale rather than just the piece under strain. Break that same application into smaller, independently deployable components, and only the parts under load need to expand. The difference shows up directly in cloud cost and performance, not just in engineering elegance.

Modernized applications solve one problem. They don’t solve the question every CISO in the room is already asking.

Can the Cloud Be Trusted with Security, Compliance, and Recovery?

Security concerns don’t vanish in a hybrid setup. They just move.

Data in transit during migration is more exposed than data sitting on a single, tightly controlled system. This makes encryption, secure transfer channels, and pre-migration validation of the target environment non-negotiable rather than optional. Once live, access controls, multi-factor authentication, and continuous monitoring help meet obligations under frameworks like HIPAA, GDPR, and PCI DSS, while protecting the business from the kind of breach that damages both operations and reputation in one stroke.

It is worth being specific about what “compliance” actually requires here, since the phrase gets used loosely. It means encryption both at rest and in transit, documented access logs that can survive an audit, and a clear line of accountability for who can touch what data and when. Most of it is standard cloud provider functionality, but it has to be configured deliberately rather than assumed to exist by default.

Disaster recovery is where hybrid cloud tends to earn its keep. Automated failover, geographically distributed replication, and scheduled backups let organizations recover from hardware failure, software error, or ransomware without depending entirely on a secondary on-premises data center.

Kyndryl’s 2025 State of Mainframe Modernization Survey found that ROI from integrating mainframe environments with cloud climbed to 297% in 2025. This is more than double the 145% recorded just a year earlier². Resilience, in other words, is not a soft benefit anymore. It is showing up directly in the return organizations report.

Security and recovery protect what you’ve already built. The next question is how fast you can keep building.

Does DevOps Belong in an IBM i Conversation?

Hybrid cloud adoption tends to stick when it comes with a cultural shift, not just a technical one. DevOps is the closer collaboration between development and operations, continuous integration pipelines, faster feedback loops. It helps organizations keep pace with the release cycles cloud environments make possible. IBM i organizations that build this discipline into their hybrid strategy tend to iterate faster and get more out of their cloud investment over time, rather than treating the migration as a one-time event.

This is not hypothetical for the platform, either. Growing use of tools like Git, Jenkins, and Ansible across the IBM i community suggests DevOps has stopped being a “modern IT” concept borrowed from elsewhere and started becoming standard practice on IBM i itself.

The shift also changes how teams think about releases. Instead of a single, high-stakes deployment a few times a year, DevOps-oriented IBM i teams move toward smaller, more frequent updates. Here, each one lower-risk simply because it is touching less at once. For teams used to carefully scheduled, all-hands deployment windows, that’s a genuine culture change, not just a tooling upgrade. It tends to take longer to embed than the migration itself, which is exactly why it is worth starting early rather than treating it as a “phase two” concern.

Good planning, the right architecture, tight security, and DevOps discipline put together ensure migrations go smoothly. Most. Here is where the rest tend to stall.

What Are the Common Challenges in IBM i Hybrid Cloud Migration?

While the business case for IBM i cloud migration is compelling, the migration journey itself is rarely straightforward. Organizations often operate complex IT ecosystems built over decades, where IBM i applications are deeply integrated with business processes, databases, and third-party systems. Moving these mission-critical workloads to a hybrid cloud environment requires careful planning to avoid operational disruptions, performance issues, and security risks.

Understanding these challenges early enables organizations to develop mitigation strategies that reduce risk and improve the success of their migration initiatives.

1. Modernizing Legacy Applications for the Cloud

Many IBM i applications were originally designed for traditional on-premises environments rather than cloud-native architectures. As a result, organizations may encounter compatibility issues when migrating legacy applications to the cloud. Older applications often depend on specific operating system versions, hardware configurations, or tightly coupled architectures that are difficult to replicate in a cloud environment.

Additionally, organizations must determine the most appropriate migration approach for each workload. While some applications can be rehosted with minimal changes, others may require replatforming or partial refactoring to take advantage of cloud capabilities.

Best practice: Begin with a comprehensive application assessment to identify dependencies, evaluate cloud readiness, and determine the most suitable migration strategy for each workload. Pilot migrations can help uncover compatibility issues before large-scale deployment.

2. Managing Data Migration and System Integration

Enterprise IBM i environments typically support multiple interconnected applications that exchange data across ERP systems, CRM platforms, databases, and external business applications. Migrating these environments involves more than simply transferring data from one location to another.

For organizations exchanging business documents with partners and suppliers, modernizing AS400 EDI integration alongside cloud migration can simplify connectivity while reducing operational complexity.

Large data volumes can extend migration timelines, while maintaining data consistency during migration adds another layer of complexity. At the same time, organizations must ensure that integrations between IBM i applications and surrounding systems continue to function seamlessly after migration.

Without careful planning, organizations risk data synchronization issues, prolonged downtime, or broken business workflows.

Best practice: Prioritize workloads based on business criticality, migrate in phases, validate integrations throughout the process, and leverage proven migration tools that support incremental data synchronization to minimize business disruption.

3. Strengthening Security and Maintaining Compliance

Security remains one of the primary concerns when moving mission-critical IBM i workloads to the cloud. Sensitive enterprise data becomes vulnerable if proper safeguards are not implemented throughout the migration process and beyond.

Organizations must also comply with industry-specific regulations such as GDPR, HIPAA, PCI DSS, and other regional data protection requirements. Failure to maintain compliance can result in financial penalties, reputational damage, and operational risk.

Cloud adoption introduces additional considerations around identity management, access controls, encryption, and continuous monitoring, all of which require a well-defined governance strategy.

Best practice: Adopt a security-first approach by implementing end-to-end encryption, multi-factor authentication, role-based access controls, continuous monitoring, and regular compliance assessments throughout the migration lifecycle.

4. Building Organizational Readiness

Technology is only one aspect of cloud transformation. Equally important is ensuring that employees have the knowledge and confidence to work effectively within a hybrid cloud environment.

IT teams accustomed to managing traditional IBM i infrastructure may need to develop new skills related to cloud operations, automation, monitoring, and security. Similarly, business users may require guidance on updated workflows and operational processes. Without adequate preparation, organizations may experience slower adoption, reduced productivity, and increased operational errors during the transition.

Best practice: Invest in structured training programs, provide hands-on learning opportunities, and establish clear communication throughout the migration process to ensure both technical teams and business users are prepared for the new environment.

5. Optimizing Performance and Controlling Cloud Costs

Moving workloads to the cloud does not automatically guarantee better performance or lower costs. Improper resource allocation, inefficient application configurations, and inadequate monitoring can lead to higher-than-expected cloud spending and inconsistent application performance.

Organizations must continuously monitor resource utilization, optimize infrastructure configurations, and align cloud consumption with business needs to realize the expected return on investment.

Performance optimization is equally important. Factors such as network latency, workload placement, storage configuration, and application architecture all influence how IBM i applications perform in hybrid cloud environments.

Best practice: Establish continuous performance monitoring and cost governance practices from the outset. Regularly review resource utilization, automate scaling where appropriate, and optimize cloud configurations to maintain both performance and cost efficiency.

How to Choose a Partner Who Actually Understands IBM i?

Plenty of cloud providers and systems integrators understand cloud. Fewer understand IBM i’s particular architecture, its dependencies, its operational quirks and that gap matters more than it sounds like it should.

• Look for a partner with a real track record on AS400/IBM i migrations specifically, not just general cloud credentials.
• Transparent security practices matter. So does a willingness to start with a contained pilot instead of pushing for a full cutover on day one.
• Ask how they have handled a migration that didn’t go according to plan. Every experienced partner has one of those stories, and how they answer tells you more about their judgment than any case study will.

For organizations without deep in-house cloud expertise, bringing in specialists early almost always costs less than fixing avoidable mistakes after the fact.

So, Where Does This Leave IBM i Leaders?

IBM i’s staying power was never really in question. Its reliability is exactly why so many critical workloads still run on it. What’s changed is the environment around it, not the platform itself.

Hybrid cloud gives IBM i organizations a way to hold onto that reliability while picking up the cost efficiency, scalability, and resilience that on-premises infrastructure alone can no longer deliver. The organizations getting this right share a pattern: they assess honestly, choose deployment models deliberately, modernize applications instead of forcing legacy code into environments it wasn’t built for, and treat security and disaster recovery as foundational rather than an afterthought bolted on at the end.

None of that requires giving up what makes IBM i valuable. With the right IBM i modernization services, organizations can preserve business-critical operations while adopting hybrid cloud capabilities at a controlled pace.

External Links:

• 1. https://power.fortra.com/resources/guides/ibm-i-data-center-2026-ibm-i-marketplace-survey-results
• 2. https://www.kyndryl.com/content/dam/kyndrylprogram/doc/en/2025/mainframe-modernization-report.pdf