Legacy mainframe applications have endured for decades and often these applications are well suited to the business's needs and provide functionality and capability that could not be easily replicated through a rewrite or replacement modernization approach.

Refactoring mainframe applications to AWS is a popular pattern pursued by many organizations and consists in automated conversion of applications in languages like COBOL to Java or C# and to leading relational databases on AWS. This approach enables applications to be in modern programming languages, with modern databases, and in platforms that the next generation of developers can easily maintain and innovate upon.

Java and C# are some of the most widely used programming languages today and often a language of choice for many IT programs in schools across the globe. Moving from COBOL to either one of these languages enables the usage of state-of-the-art IDEs, thousands of third-party libraries, and modern application architectures.

COBOL to C# white paper

Amazon Web Services (AWS) is an excellent target environment for transitioning from an IBM mainframe workload to a cloud implementation. With the security features of AWS and the ability to scale based on demand for the services, AWS offers a complete operational environment in support of mainframe workloads that have been migrated to the cloud. In addition, AWS supports innovation of the application portfolio, previously held captive by the inflexible nature of a mainframe computing model, improving the productivity of application developers and support personnel.

Migrating to AWS allows clients to leverage numerous cloud services and scale their applications on demand. Through programs such as the AWS Migration Acceleration Program for Mainframe, or AWS Public Sector Partner Program, organizations gain access to a comprehensible ecosystem of mainframe technologies and professional services to assist with migration and modernization projects and reach their transformation goals faster.

Learn how organizations can benefit from the AWS Mainframe Modernization Service >

The FastTrack Factory: 100% Automation

With pressing drivers compelling mainframe customers to look for alternatives, Astadia has successfully provided a proven path forward. By developing the FastTrack Factory - the only fully automated migration software platform on the market -, Astadia partners with clients to migrate their mainframe applications to cloud or distributed environments.

The platform provides 100% automated migration and testing, which are critical in accelerating and ensuring a successful mainframe migration, while maintaining applications’ functional equivalence.

See how organizations can reach faster time to market with reduced project risk >

A Complete Mainframe-to-Cloud Migration Solution

Astadia provides a full suite of automated migration and testing technology for transformations from one technology to another. The FastTrack software platform has one crucial consideration: each organization is different, and each migration is different. Every client has its development and design standards, patterns, and frameworks.

The platform is therefore highly configurable. It consists of several language parsers, analyzers, rule-based converters, and generators that work together to perform complex transformations on existing source code. These converters and generators can be easily configured to produce optimal code.

For example, if your organization has implemented specific standards for coding, our CodeTurn tool can be configured to incorporate those standards into its transformed application code.

Here is a quick overview of the migration platform’s main software components:  

  • CodeTurn – Provides automatic source code conversion. CodeTurn supports many different source languages, such as COBOL, Natural, and CA ADS. The most typical target languages are COBOL, Java, or .NET.
  • DataTurn - Provides specialized features for various source databases, such as Adabas, IDMS, Db2, IMS, VSAM,ISAM, and target databases such as SQL Server, Oracle, or Db2. The target database can be accessed natively without restrictions.
  • TestMatch - Automated Record and Replay testing for online and transaction-based applications such as3270, MQ, and EntireX. TestMatch provides functional tests, performance tests, and stress tests
  • DataMatch - Automated testing for data-centric and batch programs. Compares databases after running batch job on mainframe, with after running converted batch job on the target platform
  • CobolBridge – A VSCode based IDE that allows for the editing and debugging of COBOL while running Java or C# in the backend. CobolBridge uses CodeTurn and COBOL tools as part of the 'build' process, producing maintainable Java or .NET. Customers can take time to re-train COBOL developers and then decide to start maintaining Java/C#.

Learn more about the FastTrack Factory >

Licensing the FastTrack Factory: An Industry First

In addition to providing complete end-to-end services for mainframe migrations, clients or partners can choose to license the platform to deliver projects themselves. This is a critical factor when evaluating migration partners – do you have the ability to license their software?

The answer to this question must be yes, as it ensures you're dealing with a complete product that requires little manual intervention.

Often, providers in the refactoring and mainframe to cloud market will position tools that automate 70-80% of the process and require the remaining 20-30% of the development work to be done by hand. This creates both significant challenges and costs, whereas a fully automated solution will be a complete product.

The Astadia FastTrack Factory white paper

Proven Methodology

In addition to the FastTrack platform, Astadia’s mainframe migration to AWS solution relies on our FastTrack methodology, that has been developed over 20 years and refined over hundreds of mainframe migration projects.

Astadia's FastTrack process is an innovation that eliminates risk from software transformation projects and allows applications to undergo complex cross-platform migrations at the same time as normal perfective and adaptive maintenance progresses without business interruption.

With comprehensive and fully automated technology and a proven methodology focused on accelerating the mainframe migration and driving down risk, Astadia enables clients to migrate their mainframe applications to AWS at a speed and scale unlike any provider or solution in the industry.

IBM Mainframe-to-AWS Reference Architecture

The following Reference Architecture diagrams address a typical mainframe to AWS use case. However, each implementation is sure to have its own customizations and variations, which is why a thorough application portfolio inventory, assessment, and rationalization is critical to a successful outcome.

The typical mainframe migration to AWS process includes AWS components, batch requirements, programming language conversions and replacements, integration with external systems, and planning for future needs. In an actual project, you would also consider any unique features that would necessitate custom-made solutions. We would recommend proof-of-concept conversions on application subsets to test the model selected, discover any weaknesses, and prove the viability of the design.

The newly transformed applications will run as a native first-citizen application on AWS. The Astadia technology does not rely on emulators or sandboxed applications. The FastTrack Factory tooling keeps the transformed code concise, readable, and maintainable, without code bloat, by centralizing code sections within libraries and software services. These become an integral part of the generated code, delivered in source code format. There is no vendor lock in, and newly written code does not need to rely upon the source libraries.  

Modernizing mainframe applications is the most critical phase of the total project effort, even more than a typical IT project. An excellent place to begin is with a thorough assessment of the existing overall mainframe application portfolio. All aspects of the current portfolio will be inventoried and examined in detail through the assessment process, resulting in a catalog of each application, database, technology platform, and business user profile currently in use.

Once completed, the results of this application rationalization will then guide the sequence of application migration and the different modernization strategies and techniques that may be called upon throughout the entire project. To learn more about getting started with an assessment, reach out to us here.

Your AWS Environment

Amazon Virtual Private Cloud (VPC) lets you provision a logically isolated section of AWS where you launch and manage AWS resources in a virtual network that you define. It's your private area within AWS. You can think of this as the fence around systems you have in AWS. You have control over your virtual networking environment, including a selection of your own IP address range, creation of subnets, and configuration of route tables and network gateways. You can use both IPv4 and IPv6 in your VPC for secure and easy access to resources and applications.

Computing Resources

Elastic Compute Cloud (EC2) provides secure, scalable compute capacity in AWS. It serves as the foundation upon which your application sits. It's the container that holds the operating systems, application executables, and other supporting software that make up your application. Depending on your specific circumstances, you may separate some pieces into their own EC2 instances, or you may run everything into one instance. For example, maybe you'll have an EC2 dedicated to batch COBOL and another dedicated to Online. You may even segregate EC2s by applications.


Elastic Block Storage (EBS) can be thought of as a hard drive for storing data. Lots and lots of data. EBS serves as the primary storage "device" for EC2 instances running migrated applications. Another storage option is Simple Storage Service (S3). EC2 instances connect to S3 through APIs to access and store object data. S3 can be used for bulk data repositories or "data lakes" for analytics. AWS also offers Amazon Glacier (not shown above) as a low-cost, reliable service for backup and archiving of all types of data. S3 is designed to deliver 99.999999999% durability and scale past trillions of objects worldwide. These services are combined to meet the storage requirements of your mainframe applications.


Amazon's Relational Database Service (RDS)is where all your legacy relational data will reside. This includes any flat-file data that's been converted to relational, for example, all your flat files and IMS DB data that's been converted to relational and migrated to RDS. DB2 data would also be migrated here. This service is optimized for database performance. It's cost-efficient, has the resizable capacity, and is designed to reduce time-consuming database admin tasks. RDS is available in several familiar database engines, including Microsoft SQL Server, Oracle, PostgreSQL, MySQL, and MariaDB. You could also set up a DB2 LUW server instance. However, you may want to consider migrating your relational data to Amazon Aurora. This MySQL-compatible database has been optimized for AWS and can perform up to 5 times faster than MySQL. Analyzing your existing legacy databases and applications will reveal all the changes required to migrate your data to Aurora or any other RDBMS running in AWS.

Why Migrating Your Mainframe?

The IBM z/Series mainframe continues to provide a stable, dependable, and high-performance platform for large enterprises across the globe. It has proved to be an enduring system, continually out living the expectations of analysts and experts. With over 250B lines of COBOL worldwide, the mainframe lives on, running large mission-critical applications at a massive scale. With all the strengths it has to offer, the question becomes why invest in a mainframe migration?

Meredith Corporation case study

There are many documented failures, and a mainframe modernization project is often perceived as high-cost, high-risk, without a clear return on investment. At Astadia, we are answering these questions for the largest mainframe customers across the globe. No longer are migrations the pursuit of customers with 100 MIPS, but those with 10,000 MIPS, 50,000 MIPS, and more are setting the direction to exit their mainframe. Why is this happening now?

The Urgent Need for Innovation

There are several reasons why the demand for mainframe modernization is rapidly accelerating among organizations worldwide, but primarily, the need for innovation has never been more pressing. All industries face disruption, and without the flexibility to adapt and adopt new technologies quickly, businesses are at high risk of failure.

CIOs routinely report their mainframe and COBOL applications are not suited to doing business in the new normal. The pandemic accelerated digital transformation across all areas, and 5- and 10-year roadmaps have been thrown out the window. Technology's strategic importance in business is evident, and innovating is no longer a matter of optimizing budgets and addressing technical debt but a matter of survival.

The Skills Shortage Risk

The growing talent gap is a well-documented issue. Despite the best efforts of a few universities and programs, there is nowhere near an adequate amount of education to train a new generation of COBOL programmers. COBOL programmers are, on average, less than five years away from retirement, and for many, that number has been accelerated due to the pandemic and changed work-life priorities.  

Increasing License and Maintenance Costs

Lastly, there is cost. The high prices are often acutely experienced by customers running products such as CA IDMS or CA Datacom (who CA lovingly referred to as "cash cows in the basement"). AWS offers clients the opportunity to pursue significant operating cost reductions and reinvest that money into further modernization programs.

Astadia has documented references of customers saving upwards of 80%, with some of our large customers reducing their annual operating costs over $20M and achieving payback periods of less than 12 months.

IBM to AWS white paper


A mainframe migration to AWS is one of the most impactful initiatives an organization can pursue today. With significant return on investment, unlocking your legacy mainframe applications opens up a multitude of possibilities for innovation and transformation.

A two-phased approach to modernization, is a simple, but proven framework that has worked for hundreds of clients. The first phase is to retire the mainframe and land safely in your new AWS environment, followed by the second phase of adopting strategic modernization initiatives to meet your future goals.

A complete and fully automated approach enables mainframe customers to pursue modernization without compromise. Moving from COBOL to Java or C# requires a fully automated migration and testing platform, a partner with extensive experience and case studies, and a proven methodology.

There are many considerations to make when embarking on a mainframe to cloud journey. At Astadia, we have encountered over 40 different technologies on our customers mainframes, with each environment coming with its own set of challenges. If you'd like to understand how this could be possible for your organization's unique complexities, we'd love to hear from you. Fill out this form to get started.

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