Chris wick | publishings

Why Companies Still Rely on IBM i / AS400 Systems After 20+ Years

Introduction

In an era dominated by cloud computing, microservices, and AI-driven applications, it may seem surprising that many organizations still run critical workloads on technology that dates back over 20 years. The IBM i (formerly AS/400) platform, introduced in 1988, remains a cornerstone for industries ranging from banking to manufacturing, retail, logistics, and insurance. Though the branding has evolved—from AS/400 to iSeries, System i, and now IBM i—the underlying architecture has remained remarkably consistent.

What’s even more striking is that some of the world’s most critical business functions, from transaction processing to supply chain management, still run on IBM i systems. This persistence raises important questions: Why do companies remain so loyal to IBM i, despite its age? What challenges do they face in maintaining these systems, particularly when it comes to finding talent skilled in RPG (Report Program Generator) and COBOL (Common Business-Oriented Language)? And what does this mean for the future of enterprise IT?

1. The Enduring Strength of IBM i

Reliability and Uptime

One of the strongest arguments for IBM i’s longevity is its reputation for reliability. Organizations that require 99.999% uptime—such as banks, hospitals, and manufacturers—trust the platform because it simply does not fail in the way commodity server stacks often do. Crashes are rare, recovery is robust, and the system has been battle-tested across decades of continuous operation.

Integrated Architecture

Unlike modern systems where businesses must assemble separate layers of compute, storage, database, and middleware, IBM i integrates all of these in a single, tightly coupled environment. The OS includes its own DB2 database, security framework, and development tools. This integration reduces complexity, minimizes compatibility issues, and lowers the risk of misconfiguration.

Security

IBM i is widely regarded as one of the most secure enterprise platforms in the world. Its object-based architecture isolates programs and data in a way that is inherently resistant to malware and ransomware. For industries subject to heavy regulation—such as finance, healthcare, and government—this provides peace of mind that modern systems cannot always match.

Performance for Transaction Processing

The platform is particularly well-suited for high-volume transaction processing. Banks still rely on IBM i for ATM networks and payment systems, retailers use it for point-of-sale transactions, and logistics companies depend on it for shipping manifests and inventory management.

2. Loyalty Rooted in Business Continuity

Companies that adopted IBM i decades ago have found that it provides the one thing executives value above all else: business continuity. Migrating mission-critical workloads off the platform is seen as high-risk and expensive. For many organizations, the phrase “If it isn’t broken, don’t fix it” is taken literally.

Cost of Migration

Replatforming to cloud-native systems requires millions in investment, years of planning, and enormous retraining costs. Many businesses evaluate these costs and conclude that it is cheaper to modernize their IBM i applications incrementally than to rip and replace.

Institutional Knowledge

Entire business processes—such as order fulfillment, billing cycles, or supply chain tracking—are deeply embedded in RPG or COBOL codebases that have evolved for decades. These systems reflect not just technology, but also business logic that is unique and irreplaceable. Rewriting them from scratch risks losing nuances that only long-serving developers fully understand.

Vendor and Industry Support

IBM continues to invest in the platform, releasing updated hardware (Power Systems) and OS versions. Many industries also offer vertical solutions built on IBM i, meaning companies have access to tested and supported applications specifically designed for their sector.

3. Challenges in Maintaining Legacy Code

While the platform itself is robust, the real challenge lies in maintaining the code written in RPG and COBOL.

Shrinking Talent Pool

RPG was once a dominant programming language in the business world, but universities stopped teaching it decades ago. Younger developers focus on modern languages like Python, Java, and JavaScript. As senior RPG and COBOL programmers retire, companies are left with fewer skilled professionals able to maintain or extend their critical applications.

Knowledge Silos

In many companies, the same RPG developer has been working on the system for 20 or 30 years. Their personal knowledge of quirks, patches, and business rules often isn’t fully documented. When they retire, that knowledge risks disappearing, leaving organizations exposed.

Recruiting Difficulties

Job postings for RPG or COBOL developers often remain open for months without qualified candidates. Even when companies do find talent, salaries can be high due to the scarcity of expertise. Younger developers are often reluctant to enter these fields, perceiving them as “dead-end” compared to working in cloud-native or AI-driven environments.

Limited Tooling and Ecosystem

Although IBM has modernized the platform with tools like RDi (Rational Developer for i) and support for open-source languages, the ecosystem around RPG and COBOL is far smaller than that of modern frameworks. This makes development slower and less attractive to engineers used to GitHub, npm, and containerized workflows.

4. Why Companies Remain Loyal Despite the Challenges

Even with the hiring crisis, many companies double down on their IBM i loyalty. There are several reasons for this:

  1. Proven ROI – The system has already delivered decades of reliable service, and the cost-to-value ratio remains high.
  2. Risk Aversion – CIOs know that migrating away could introduce outages, errors, or compliance failures.
  3. Vendor Roadmap – IBM has continuously updated the platform, demonstrating a commitment to support for the foreseeable future.
  4. Modernization Options – Instead of migration, companies can modernize their RPG and COBOL applications by wrapping them in APIs, integrating with web services, or moving workloads to hybrid environments.

This loyalty is not blind nostalgia—it is a rational assessment of business risk versus reward.

5. Modernization Strategies and Their Limits

Many organizations attempt to bridge the gap between legacy and modern IT through incremental modernization:

  • API Enablement: Wrapping RPG programs with REST APIs so they can integrate with modern applications.
  • Open Source on IBM i: Using Python, PHP, or Node.js alongside RPG/COBOL to extend functionality.
  • Code Conversion Tools: Automated tools exist to convert RPG/COBOL into Java or C#, though results often require significant manual cleanup.
  • Hybrid Cloud: Running IBM i workloads on IBM Power Systems in the cloud, rather than on-premises hardware.

While these strategies extend the lifespan of IBM i, they don’t solve the talent shortage. Someone still needs to understand the underlying RPG and COBOL code.

6. The Future Outlook

The reliance on IBM i presents a paradox:

  • On one hand, the platform is so reliable and trusted that businesses are reluctant to abandon it.
  • On the other hand, the shrinking pool of RPG/COBOL programmers poses an existential risk.

Some possible future scenarios include:

  1. Sustained Coexistence: IBM i continues to thrive as a specialized backbone for critical workloads, augmented by modern layers for customer-facing applications.
  2. Gradual Migration: As talent becomes scarcer, organizations are forced to prioritize migration projects, even at high cost.
  3. AI-Assisted Maintenance: LLMs and code-generation tools could help bridge the gap by translating RPG/COBOL into modern languages or assisting with debugging and documentation.
  4. Market Consolidation: Companies unable to sustain IBM i systems may merge with competitors that still have the talent and infrastructure to maintain them.

Conclusion

The IBM i / AS400 story is one of endurance, loyalty, and challenge. For over 20 years, it has served as the backbone of industries that demand reliability, security, and performance. Companies remain loyal because the platform delivers continuity, stability, and ROI unmatched by many modern alternatives.

Yet this loyalty comes at a cost: the scarcity of RPG and COBOL developers. As the talent pool dwindles, organizations face mounting risks in sustaining their mission-critical systems. The irony is clear: the technology is rock-solid, but the human expertise around it is fragile.

The future of IBM i may therefore depend less on the platform itself—which IBM continues to support—and more on how companies manage the human capital crisis. Whether through retraining, modernization, or AI-driven solutions, businesses must address the skills gap to ensure their IBM i systems remain not only functional but also strategically valuable in the decades to come.