Mainframe

In today's rapidly evolving tech landscape, modernizing legacy mainframe systems is crucial for organizations to remain competitive.

At Keyhole Software, we specialize in transforming outdated mainframe applications into cloud-ready, scalable solutions that streamline operations, improve performance, and reduce costs. Our AI-powered modernization tools accelerate this transition, enabling faster and more efficient migrations.

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Mainframe Modernization Services

Modernize legacy mainframe applications with Keyhole Software. Reduce costs, improve agility, and enable new capabilities like AI and cloud computing with our proven modernization consulting services.

Advisory & PoC Services

Comprehensive architectural assessments and actionable roadmaps with Proof-of-Concepts (PoCs) to minimize risks and validate strategies.

Application Development

Building custom web, desktop, or mobile .NET applications from start to finish or extending existing apps with new features that meet your requirements.

Code Transformation & Application Migration

Streamlined re-platforming for rapid deployment, including COBOL-to-Java or COBOL-to-C# migrations using advanced syntax tree tools.

Cloud Enablement

Transition to AWS, Azure, or Google Cloud platforms and optimize for serverless or container-based architectures.

Why Choose Keyhole For Mainframe Modernization?

Award Seal for Top App Modernization Service Company in Kansas 2025

Award Seal for Top Software Developers Award in Kansas by Clutch

The Keyhole Difference

We stand out through our deep expertise in mainframe modernization, blending cutting-edge technology with proven strategies. Here’s what you need to know before we tackle your project:

Expert Execution: Our consultants average 17 years of experience, including recent COBOL, RPG, Model 204, and AS/400 migrations.

Trusted by Clients: 78% of projects last year were with repeat clients, reflecting our consistent success in modernization.

U.S.-Based Team: Long-term employees ensure aligned, hands-on execution tailored to your business needs.

Technology-Agnostic Approach: We select the best-fit tools and modernization strategies based on your business needs—whether rehosting, rearchitecting, or full cloud migration.

If you're looking for expert modernization change agents that your business can rely on, look no further than Keyhole Software.

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Why Clients Trust Keyhole

At Keyhole Software, we’re leaders in setting best practices for mainframe modernization. Our expert consultants employ industry-leading strategies to ensure seamless migrations and future-proof solutions. We focus on scalable, cost-effective transformations using modern technologies that enhance the efficiency of your legacy systems. Trust us to guide your business toward sustainable, growth-driven solutions.

Leveraging AI tools like our Keyhole-developed EnterpriseGPT, we accelerate mainframe modernization by automating code translation and enhancing migration speed. Our AI-driven approach reduces manual effort and speeds up cloud transitions while improving accuracy and efficiency.

By integrating AI, we offer innovative solutions that help your organization achieve modern, cloud-ready systems faster and more cost-effectively.

Mainframe Modernization Case Studies

Legacy Systems Modernization We’ve Delivered For Clients

Keyhole Software specializes in modernizing mainframe, AS/400, RPG (I-IV), and COBOL-based systems, transforming legacy applications into scalable, efficient, and future-ready Java-based solutions. This complex challenge requires a combination of the right tools, expertise, and strategic planning.

Our experience spans industries such as financial services, manufacturing, logistics, healthcare, and retail, where we have successfully delivered mainframe modernization solutions that enhance performance, reduce costs, and ensure long-term sustainability.

Use Case: Cost Reduction Through AI Acceleration, Legacy COBOL Batch Process Modernization, Cloud-Native Batch Job Orchestration

Keyhole Software successfully modernized a COBOL batch processing application to Spring Batch using EnterpriseGPT, an AI-powered tool that streamlined code analysis, migration, and development. This AI-assisted approach accelerated the process by 20–30%, reducing manual effort while improving scalability, maintainability, and performance.

By integrating cloud-native orchestration with SCDF, the modernized solution ensured efficient batch job execution, demonstrating how AI-driven modernization can cut costs, reduce timelines, and seamlessly transition legacy systems to modern architectures.

Case Study: AI-Accelerated COBOL Modernization to Spring Batch

Use Cases: M204 Legacy Application Modernization, Scalability, Failover Management, and Continuous Integration

Keyhole Software helped a national transporter modernize its nearly 1,000 existing Model 204 batch applications by converting them to Java solutions. This conversion supported scalability, durability, and on-demand deployment through a microservices architecture. Key features included an API Gateway for online interfaces, service discovery for scalable runtime environments, and a Jenkins-based CI process enhanced with Docker for containerized deployments.

Project Highlight: M204 To Spring Boot Microservices

Use Case: Batch Processing Automation, Best Practices Technology Education, Automated Testing

Keyhole Software assisted a financial institution in modernizing its enterprise batch processing applications by converting COBOL-based processes to Java-based solutions using the Spring Batch framework. Key highlights included implementing unit testing using Mockito, training client staff on Spring Batch, and mentoring on modern batch processing best practices.

Project Highlight: Modernization: COBOL Batch Processing to Spring Batch

Recent Case Study

AI-Accelerated COBOL Modernization For Grocery Client, picture of generic produce

AI-Accelerated COBOL Modernization to Spring Batch

"This AI-assisted modernization approach accelerated the COBOL migration process by 20–30%, reducing manual effort in Spring Batch implementation while improving scalability, maintainability, and performance."
- Successful Project Outcome

View Case Study

Related Services

Enterprise Modernization

Cloud Native Consulting

Microservices Consulting

Why Modernize Mainframe Applications?

Mainframes have been essential for industries like banking, insurance, healthcare, and logistics, providing high availability for critical apps and low-latency transaction processing. While these systems have served well for decades, the tech landscape has evolved significantly since the 1970s. Today, businesses need modern solutions that meet requirements for performance, scalability, and flexibility, which can be achieved through mainframe modernization.

Mainframe Pain Points

Performance Problems - The volume of messages/transactions through the system increases latency and causes cascading failures.

Scalability Woes -The vertical limits of scalability are being hit – meaning the machines cannot get bigger fast enough to handle increases in capacity.

Deployment Woes - Everything has to be deployed as one unit and/or is tightly coupled to all of its infrastructure.

Resource Woes - The engineers who worked on this system originally are retiring, and the programming language is not being taught anymore.

Benefits To Expect After Modernizing Your Mainframe

Modernizing legacy systems addresses the performance issues that plague COBOL-based applications:

Improved Throughput: Transitioning to modern platforms like microservices or cloud-native architectures allows systems to process high volumes of messages or transactions without bottlenecks.
Enhanced Reliability: Modern frameworks and technologies offer built-in tools for monitoring, logging, and error recovery, minimizing the risk of cascading failures.
Real-Time Processing: Adopt real-time data processing to meet the increasing demand for instant insights and faster transaction handling.

Modernization ensures your systems are equipped to scale dynamically as your business grows:

Horizontal Scaling: Unlike the vertical limits of legacy systems, modern solutions embrace horizontal scaling—adding more servers or containers to distribute the load seamlessly.
Cloud-Native Scalability: Leverage the elasticity of cloud platforms like AWS, Azure, or Google Cloud, which scale up or down based on demand.
Future-Proof Infrastructure: Adopt containerization (e.g., Docker, Kubernetes) to enable rapid resource provisioning and capacity expansion.

Modern architectures transform painful, monolithic deployment processes into seamless, agile workflows:

Continuous Integration & Deployment (CI/CD): Implement modern DevOps practices to automate testing, integration, and deployment, reducing downtime and manual intervention.
Decoupled Components: Transition to microservices architectures, enabling independent deployment of services without affecting the entire system.
Faster Time-to-Market: Efficient deployment pipelines ensure quicker feature releases and updates to respond to market demands.

Modernizing your systems ensures access to a broader talent pool and reduces reliance on outdated expertise:

Skilled Workforce: Languages like Java, Python, and JavaScript are widely taught and used, making it easier to hire and train engineers.
Community Support: Modern technologies have active developer communities, extensive documentation, and a wealth of third-party tools for troubleshooting and innovation.
Knowledge Retention: With modern systems, businesses can onboard new developers faster and rely less on retiring engineers with specialized knowledge.

Modernizing your legacy COBOL systems isn’t just about solving current challenges—it’s about preparing your business for the future. With increased agility, better scalability, and a larger talent pool, you can respond faster to changing markets and innovate with confidence.

Mainframe Modernization Services

Keyhole’s Approach For Migrating Mainframe Systems

At Keyhole Software, our expert consultants help organizations modernize legacy mainframe, AS/400, RPG (I-IV), and COBOL-based systems for improved performance, scalability, and maintainability. Whether you need to rehost, refactor, rearchitect, or replatform, we ensure a smooth transition with minimal disruption.

Explore our key legacy application modernization services below:

Keyhole Software provides a detailed modernization plan, outlining the best approach—whether it’s rehosting on cloud, refactoring code for microservices, or rearchitecting for containerization. We help mitigate risk, minimize downtime, and optimize your IT investments.

Key Modernization Approaches Considered

Replatforming – Moving mainframe workloads to a new platform (e.g., cloud) without changing the underlying code.
Rehosting – Moving the mainframe applications to a new environment, typically using virtualized infrastructure.
Refactoring – Updating the code to improve performance or flexibility, without changing its core functionality.
Rearchitecting – Redesigning the architecture to ensure scalability, flexibility, and alignment with modern technologies.
Encapsulating – Wrapping legacy applications with APIs or modern interfaces for integration with newer systems.

Video: Strategic Portfolio Modernization

Our expert software consultants execute the modernization process, utilizing modern technologies like Java, Spring Boot, Spring Batch, .NET, Kubernetes, Docker, and cloud platforms. Whether transitioning to AWS, Azure, or Google Cloud, we ensure seamless migration with optimized performance.

Cloud & API Integration
We also help modernize mainframe systems by integrating APIs, microservices, and cloud-based platforms, enabling real-time data access, enhanced scalability, and cost efficiency.

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Recent Review

"Our experience with the Keyhole development team has been excellent.

One of the biggest differences compared to other consulting teams I have worked with was their commitment to fully solving the problem from start to finish. Rather than just delivering the code and moving on, they ensured everything worked as expected before considering a task complete."
- Michael Stark, Engineering Manager, Brightway Insurance

Recent Legacy Modernization Thought Leadership

At Keyhole Software, we’re passionate about equipping enterprises with the knowledge and strategies needed to modernize legacy COBOL and mainframe systems effectively. With decades of experience in transforming mission-critical applications, our thought leadership in this domain serves as a trusted resource for organizations navigating the challenges of modernization.

Modernizing Cobol Applications

What is Mainframe Modernization & How Can My Business Benefit From It?

White Paper: COBOL Modernization Strategy with Spring Batch

View More Modernization Articles

Client Questions

Here are some frequently asked questions clients have had about Mainframe Modernization services.

See Our Clients

View Our Successes

We provide flexible engagement models to match your project needs:

Software Outsourcing
Our project management + software development team builds end-to-end solutions for you.

Dedicated Dev Teams
Embedded teams for long-term modernization efforts.

Fractional & Advisory Services
Our senior software leaders provide strategic guidance to drive digital transformation.

Staff Augmentation
Our Additional skilled experts to accelerate your team’s progress.

Learn More

Keyhole Software tailors modernization strategies to fit your business needs, including:

Rehosting: Lift-and-shift applications to modern infrastructure with minimal changes.
Replatforming: Automate code transformation (e.g., COBOL to Java) for a functionally equivalent system.
Refactoring: Optimize and restructure existing code for better performance and maintainability.
Rearchitecting: Redesign applications using modern architectures like microservices or cloud-native frameworks.
Rebuilding: Completely rewrite applications while preserving core functionality.

Replatforming involves analyzing legacy code structures and using compiler-compiler software to automate transformation into modern languages like Java or C#. This approach provides a faster modernization path with minimal business disruption.

Pros:

Reduces manual effort—automated transformation replaces costly rewrites.
Provides insights that help eliminate unnecessary legacy code.
Faster implementation compared to rebuilding from scratch.

Cons:

Translated code retains technical debt; legacy inefficiencies may persist.
Performance may not match the original mainframe’s optimization.

With optimization tools like the Keyhole Syntax Tree Transformer and Parser, clients can achieve predictable results and significant time and budget savings.

Yes! We take a technology-agnostic approach, ensuring we use the best tools and frameworks for your unique modernization needs. Whether your project requires Java, .NET, or JavaScript solutions, our consultants bring deep expertise in a range of technologies. We prioritize business goals over rigid tech stacks, allowing us to design flexible, scalable, and efficient solutions tailored to your enterprise. Our approach ensures that modernization aligns with your infrastructure, team capabilities, and long-term strategy.

Ready to Modernize Your Mainframe? Let’s Talk.

Keyhole Software brings the expertise, strategy, and hands-on execution needed to modernize your legacy systems—efficiently and with minimal risk. Whether you're replatforming, refactoring, or rebuilding, our consultants ensure a seamless transition tailored to your business goals.

Contact us today to discuss your mainframe modernization needs.