Practice Lead - Mainframe
May 23, 2025
Things move so rapidly on the internet, businesses must come up with new ideas, grow larger, and adjust to market trends quickly. Many people consider mainframe legacy systems to be impediments to the progress of digital transformation. That’s where mainframe migration comes into play. Various industries are moving ahead with this strategy to achieve agility, save money, and modernize how they use technology.
However, mainframe migration isn’t without its challenges. A blend of changes to systems, how the company is run, and how things are managed is necessary, and it all needs to be handled accurately.
Top 5 Challenges in Mainframe Migration & Their Solutions
In this comprehensive blog, we delve deep into the top five challenges companies face during mainframe migration and how to overcome them effectively using best practices and proven technologies.
1. Complexity of Legacy Systems
For years, companies have relied on mainframes for their stability and support of key activities. Yet, having been around for so long means that the systems have grown more complex. Often, these systems have millions of lines of code written in older languages such as COBOL, PL/I, or Assembler. Besides, they are often designed with tightly integrated applications, their own business rules, and a variety of ways to access data.
Popular Technical Problems:
- Lack of documentation
- High interdependencies among modules
- Proprietary or obsolete middleware
- Platform-specific customizations
Solution:
You need to have a complete system discovery and a list of applications. Using Micro Focus Enterprise Analyzer, IBM ADDI, or Royal Cyber’s internal analyzers, companies can discover unknown dependencies and create maps that illustrate the application’s workflows.
After you assess everything, put your applications into six groups: retire, retain, rehost, re-platform, refactor, and rebuild. Thanks to this classification, it is clear how to move forward to meet business goals.
This is where automation is most important. Use both parsers and converters to turn COBOL logic into Java or .NET code whenever it is possible to do this. Use static analysis of code to pinpoint both reusable blocks and components that can be removed. Because of AI/ML, the platform suggests code improvements and efficient scripts for automation.
2. Data Migration and Integrity Risks
A lot of structured and unstructured information commonly resides in mainframes and is kept safe in VSAM, IMS, or DB2 databases. Migrating this data to modern storage systems in AWS without compromising integrity is one of the most critical aspects of mainframe migration.
Key Concerns:
- Schema mismatches
- Data format incompatibilities
- Transformation logic errors
- Data validation and reconciliation gaps
Solution:
The ETL process should be part of the structured strategy you follow for migrating data. When working with structured data, services such as AWS Glue, Talend, and Informatica automate a lot of the process. Store and transmit data using Apache Avro or Parquet formats because it allows schema integrity.
Set up steps and ways to validate that data is correct. AWS DMS helps move updates from your mainframe to the cloud as they happen so your business is not interrupted during the migration.
There are powerful data profiling and validation systems in Royal Cyber that are set up for single-record fields, matching and validating references, and dealing with batch data. All the data transfers should include AES 256-bit encryption and checksum verification at both locations.
3. Skill Gaps and Resource Constraints
Discussing the impact of people in this field isn’t common, but it is very important. Often, engineers who are getting ready to retire look after mainframe systems. However, many in the existing workforce do not have experience working with JCL, CICS, and DB2.
Common Gaps:
- Inadequate knowledge of legacy systems
- Lack of cloud-native development experience
- Shortage of skilled professionals for hybrid environments
Solution:
Fix this issue by giving targeted training. Royal Cyber offers workshops and mentorship programs to upskill teams on AWS mainframe modernization frameworks. Make sure the organization keeps a hybrid team of staff working on both traditional and new cloud technology.
In practice, set up simulated environments so that new engineers can explore without harming live systems. Azures integrates DevOps pipelines to automate testing and deploying code, which helps new developers join projects safely.
Thanks to AWS CodeBuild, CodeDeploy, and CodePipeline, following CI/CD best practices, is now quite easy during the transition. Make sure to capture each part of development, from changes in configuration to tests of new features, with platforms like Confluence or GitHub Wikis.
Read our case study: Dynamic Service Endpoint Lookup with DataPower & GitLab for a Leading FinServ
4. Downtime and Business Continuity Concerns
Release delays cannot happen in important areas like banking, healthcare, and telecommunications. Just a short amount of downtime can cause great harm to both profits and the brand. Consequently, almost no downtime is the most important goal during the migration.
Real-world Risks:
- Broken integrations with downstream systems
- Delayed data synchronization
- Application compatibility issues
- Performance degradation
Solution:
- Protect your organization from interruptions by selecting proven ways to move your services.
- With lift-and-shift, applications are moved to containers or VMs using little code alteration.
- Revamp certain sections while maintaining what the platform does best
- Split up single applications into microservices or create them as serverless solutions
Use the parallel run and blue-green deployment methods. Traffic should be routed differently, supported by both Elastic Load Balancing and Route 53, during the move from your old network to the new one. Use Amazon CloudWatch, Prometheus, and Grafana dashboards to keep your applications under surveillance.
Royal Cyber initially applies phased migration, putting non-priority applications into development and testing them vigorously and with Apache JMeter prior to moving everything to the live server.
Watch our webinar: Mainframe Source Code Management Migration to GitHub
5. Security and Compliance Issues
Mainframes that regularly handle sensitive financial and government records must be very secure. Storing this data with a shared cloud service leads to questions about access, where the data will be kept, and whether the company meets legal standards.
Compliance Mandates:
- HIPAA (Health)
- PCI-DSS (Financial)
- The EU General Data Protection Regulation
- Corporate Governance as per SOX
Solution:
Use a model that means every user and device on your network must be verified before access is allowed. Ensure your data is protected by storing it with AWS KMS and make use of MFA for users with IAM.
With AWS Config, CloudTrail, and Security Hub, you can check for errors in your policies and enforce compliance if you use Docker or Kubernetes secure containers by using Aqua Security or Prisma Cloud.
Our services include detailed security assessments and cloud management systems. Automated policy checks, compliance records, and reports on vulnerabilities suited for audits are all part of these features.
You may also like: Endevor to GitHub: Modernizing Mainframe Development for the Cloud Era
The Royal Cyber Advantage in Mainframe Migration
For over two decades, Royal Cyber has provided high-quality mainframe modernization services that match your needs. Royal Cyber supports you all the way, from initial feedback and planning cloud-native solutions to automatic data migration and after-deployment assistance.
The AWS-certified staff works hand in hand with clients to ensure migrations run smoothly by mixing automation tools, AI analysis, and solid project management methods.
Final Thoughts
Mainframe migration is not just a technical project; it’s a transformational journey that reshapes how organizations operate and innovate. Still, there are many obstacles in migration—from challenging technical aspects to maintaining clean data, having enough resources, and dealing with security matters—and a smart plan can greatly benefit the business.
By leveraging the power of AWS mainframe modernization, adopting best practices, and collaborating with industry leaders like Royal Cyber, enterprises can ensure a smooth transition to future-ready IT environments.
Is it time to update your website? Contact Royal Cyber now to upgrade your old systems to modern, flexible, and powerful cloud systems.
Author
Numra Haroon
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