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In this lesson we’ll cover AWS Mainframe Modernization and how it helps organizations migrate and modernize mainframe applications to AWS-managed runtimes. The service not only moves workloads from on-premises mainframes to the cloud, it also provides tools for modernizing runtimes, developer tooling, and delivery pipelines to accelerate ongoing application development and operations. Key capabilities include:
  • Assessing existing mainframe applications and dependencies.
  • Updating or developing code in legacy languages such as COBOL or PL/I.
  • Implementing automated CI/CD pipelines and managed runtime environments.
  • Choosing a migration strategy—automated refactoring or replatforming—based on business and technical goals.

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Refactoring

Refactoring transforms legacy mainframe artifacts so they run in modern cloud-native environments. This typically involves code and data conversion and often requires rewriting or adapting portions of the application so it integrates with modern platforms, frameworks, and toolchains. Highlights:
  • Automated transformation of business logic, data access, and interfaces into components suitable for modern runtimes.
  • Opportunity to enable service-oriented or microservice-based architectures and modern developer workflows.
  • Better long-term maintainability and ability to leverage modern CI/CD, containerization, and observability tools.
AWS partners with Blu Age to provide automated refactoring solutions:
  • Blu Age offers an end-to-end transformation workflow that helps convert COBOL/PL/I applications into modern application components.
  • Typical automated refactoring steps:
    • Inventory analysis to discover application components and assets.
    • Dependency analysis to map external and internal interactions.
    • Automated transformation of source code and artifacts into target runtimes.
    • Scenario capture and automated validation to ensure behavior matches expectations after transformation.
  • External partner: Blu Age

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Replatforming

Replatforming moves your mainframe application to a different host or runtime without changing the source code or business logic. It is essentially a lift-and-shift approach that gets workloads into the cloud quickly and with minimal code changes. When to choose replatforming:
  • Primary goal is fast migration with minimal code modification.
  • Short-term cost and time constraints outweigh the need for architectural modernization.
  • You plan to modernize incrementally after migrating to the cloud.
A slide titled "AWS Mainframe Modernization Options" showing icons for Refactoring and Replatforming. The center panel lists Blu Age services like inventory analysis, dependency analysis, automated code transformation, and scenario capture and management.
Which approach to choose depends on your priorities:
  • Choose replatforming for quick migrations with minimal source-code changes.
  • Choose refactoring to modernize the application stack, enable microservices or macroservices, and adopt modern developer tooling and deployment models.
Comparison at a glance:

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Other features of AWS Mainframe Modernization

  • Assess: The assessment capability discovers applications, maps dependencies, and estimates the scope and effort required for migration and modernization.
  • Refactor (Blu Age): Automate conversion of legacy languages and architectures into modern components and access Blu Age insights directly from the AWS console.
  • Replatform: Move applications to AWS without changing source code or recompiling when appropriate.
  • Integrated development environment (IDE): On-demand IDEs allow developers to write, edit, debug, compile, and unit test code with smart editing and instant feedback.
  • Managed runtime environment: AWS provides managed runtime clusters that monitor workloads with self-healing compute and automated scaling to keep enterprise workloads running.
  • Built-in CI/CD: Integrated CI/CD capabilities enable more frequent and reliable code delivery, accelerating migration, increasing quality, and reducing operational risk.

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Decision checklist

  • Run an assessment first to discover code, data, and dependencies.
  • Align migration strategy with your business timeline and modernization goals.
  • Use replatforming if you need speed and minimal disruption.
  • Use refactoring if you want long-term modernization, microservices adoption, and improved developer experience.
When planning a migration, run an assessment first to understand the effort, dependencies, and risks. Use replatforming for quick migrations and refactoring when you need long-term modernization and improved developer productivity.

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