Migrate RPG on AS/400 (IBM i) to a Web App

To migrate an IBM RPG application on AS/400 (IBM i / iSeries) to the web, you keep the DB2 for i data, rebuild the green-screen business logic as a browser-based application, and retire the 5250 terminal interface rather than screen-scraping it. At P-Soft (Barsavosh Fanavaran) we analyze your RPG, RPGLE, and 5250 display files, migrate or connect the DB2 for i data, and rebuild the software as a responsive web app. These systems often run core ERP, finance, and manufacturing, so we move carefully to preserve every rule your business depends on. This service is part of our wider legacy software rescue practice.

Why green-screen RPG is a liability now

AS/400 and IBM i hardware is dependable, but the aging RPG applications and 5250 interfaces on top of it hold modern businesses back. The problem is rarely the database; it is the code and the terminal front end.

  • Green-screen 5250 interfaces: character-mode screens are slow to learn, cannot be used on mobile, and look dated to new staff and customers.
  • Aging RPG and RPGLE code: decades of layered logic, often with little documentation and original authors long gone.
  • Scarce RPG programmers: hiring or retaining RPG developers is hard and costly, which makes every change risky.
  • Hard to integrate and mobilize: connecting green-screen apps to web services, portals, or phones is awkward and brittle.

Our migration approach

We do not screen-scrape your 5250 screens or wrap the old programs in a thin browser shell. Those shortcuts keep every limitation of the original. Instead we rebuild the business logic on a modern web stack while protecting your DB2 for i data.

  • Map the logic: we read the RPG and RPGLE programs and display files to capture exactly how each process works, including the undocumented rules staff rely on.
  • Preserve the data: we keep your DB2 for i data intact, migrating it to a modern database or integrating with it depending on your cutover plan.
  • Rebuild as web: the new application is a clean, maintainable codebase. Where you want capabilities the old system never had, our custom software development team adds them.

What you get

You move from a green-screen, single-site tool to a modern application fit for how teams work today.

  • Web and mobile access: staff use the system from any browser, on desktop or phone, in the office or remotely.
  • 50+ concurrent users: the web architecture supports many simultaneous users with room to grow.
  • Role-based access: fine-grained permissions replace coarse green-screen menu security.
  • Automated backups: scheduled, tested backups protect your business data.

If you are deciding whether to rebuild for the browser or keep an installed client, see our comparison of web vs installed software. Because RPG systems so often run core operations, our ERP software guide is useful background for data-heavy manufacturing and finance rebuilds.

How the project runs

We deliver remotely with English-language support at every stage. A typical engagement has four phases.

  • Audit: we review the RPG code, DB2 for i schema, and current 5250 workflows, then agree a clear scope.
  • Rebuild: we build the web application and verify each screen and rule against the green-screen original.
  • Data migration: we move or connect your DB2 for i data, reconcile it, and run parallel checks before cutover.
  • Training: we train your users and provide documentation so your team owns the new system.

Frequently Asked Questions

Can you keep my DB2 for i data?

Yes. Your data is preserved. We either migrate it into a modern database or integrate with DB2 for i, and we reconcile every record before go-live.

Is this just a web wrapper around my green-screen app?

No. We rebuild the business logic as a genuine web application, so you gain a modern, maintainable system rather than the old 5250 behavior behind a browser.

We have almost no RPG documentation left. Can you still migrate?

Yes. We reconstruct the rules by reading the RPG and RPGLE source and display files and by working with your staff, so undocumented logic is captured.

Do you support international customers remotely?

Yes. The entire project is delivered remotely with English support. We make no false claims about local offices or certifications; the delivered application is the proof of our work.

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