AS400 Modernization Center
AS400 modernization does not always mean migration. This section covers green screen modernization, API enablement, cloud integration, and when it makes sense to stay on IBM i.
Modernizing an AS400 or IBM i environment does not require leaving the platform. This section breaks down the real options: green screen UI upgrades, API integration, cloud connectivity, database modernization, and strategic migration decisions.
Articles in This Hub
AS400 API Integration
Exposing existing RPG and COBOL program logic through APIs lets an AS400 or IBM i system connect to mobile apps, e-commerce platforms, and partner systems without rewriting decades of business logic. This is usually the highest-leverage modernization step an IBM i shop can take.
AS400 Application Modernization
Application modernization, refactoring RPG into free-format ILE code, modularizing monolithic programs, and introducing new languages alongside existing logic, is the broadest and highest-risk modernization category. It is also the one most often confused with a full migration, when the goal is almost always to extend the application's life, not replace it.
AS400 Cloud Integration
IBM i does not run on general-purpose public cloud infrastructure, but that does not mean AS400 environments are cut off from cloud services. Backup and disaster recovery, hybrid application architectures, and IBM's own Power-based cloud hosting are all realistic paths.
AS400 Database Modernization
Many AS400 databases still rely on decades-old DDS-described physical and logical files. Converting them to modern SQL-defined DB2 for i tables and views unlocks standard tooling, better performance options, and easier integration, without requiring a database migration to a different platform.
AS400 Migration Myths
"AS400 is dead," "nobody knows RPG anymore," and "modernizing means migrating" are among the most persistent myths driving unnecessary and expensive AS400 migration decisions. Here is what each claim gets wrong.
AS400 Modernization Explained
AS400 modernization means updating how an IBM i environment looks, connects, and is built, not replacing the platform underneath it. Understanding the five modernization categories, and picking the right one for the actual problem, is the difference between a focused project and an over-scoped migration.
Green Screen Modernization
Replacing the 5250 green screen interface is usually the first modernization step organizations take, because it is visible, relatively low-risk, and does not require touching the underlying RPG or COBOL logic. Screen wrapping, rehosting, and native web front ends are the three main approaches.
When Not to Migrate Off AS400
Migration off AS400 is sometimes the right call, but it is decided correctly far less often than it is proposed. Heavy custom business logic, strong database reliability requirements, and unclear replacement ROI are the clearest signals that modernization, not migration, is the better investment.