In this post, I will show you the top mainframe modernization companies for cloud migration in 2027.
Cloud migration from mainframe isn’t one decision. It’s a sequence of decisions that compound on each other. Which workloads move first. Which stay on mainframe indefinitely. Which need to be refactored before they can run anywhere else.
If you don’t get the sequence right, you won’t actually be migrating to the cloud – you’ll just be shifting your technical problems to a more expensive system.
If you’re looking to talk to someone about updating your software, it’s a good idea to check out Recode first. They have a platform that helps you find and compare companies that specialize in modernizing software, moving applications to new systems, and transforming old technology.
Table of Contents
1. Corsac Technologies
Website: corsactech.com
Location: United States
Founded: 2007
Team size: 50-249
Corsac Technologies has a clever way to update old systems using artificial intelligence. They use it to quickly figure out how old systems work, what they need to run, and what might go wrong when moving them to the cloud. The problem with moving old mainframe systems to the cloud is that you can’t just pick them up and move them until you really understand what they do, what they rely on, and what will stop working if you change something. A lot of companies learn this the hard way, right in the middle of trying to make the switch. It’s like trying to move a house without knowing what’s inside or how it’s held together – you need to know what you’re dealing with before you can make a smooth move.
Here’s how it works: before making any decisions about moving to the cloud, Corsac’s RAG architecture takes a thorough look at the entire mainframe codebase. This involves mapping out all the dependencies that need to be considered for a successful migration. The Multi-Agent Swarm is a key part of this process, as it identifies which components are ready to move to the cloud and which ones need to be transformed first. It also uncovers any hidden dependencies that could cause problems if they’re not addressed before the migration. The end result is a clear picture of what the migration will entail, including a dependency graph, a complexity heatmap, and a tech debt audit. This gives teams a solid foundation for planning their migration, based on a deep understanding of the system they’re working with.
Here’s how companies can move their old systems to the cloud without disrupting their business. They use a strategy called Strangler Fig, which helps them do this gradually. The old system keeps running while the new cloud-based parts are introduced one by one. This way, if something goes wrong, they can quickly switch back to the old system. This approach is used with several big cloud providers like Amazon, Microsoft, and Google. It also meets strict security standards like SOC 2, HIPAA, and GDPR, which ensures that sensitive data is protected.
Key differentiator: AI-driven dependency mapping that informs cloud migration architecture before execution — migration decisions made from evidence, not assumptions
2. Reliqsy
Website: reliqsy.com
Location: United States
Founded: 2014
Reliqsy brings together artificial intelligence and the know-how of experts in modernizing and moving systems to the cloud. They use a smart approach that relies on AI to look at old mainframe code, figure out what it does, and speed up the process of rewriting and moving it to the cloud. When it comes to cloud migration, Reliqsy keeps the old mainframe and the new cloud databases in sync throughout the entire move — not just at the final cutover. This way, if something goes wrong at any point, you don’t have to deal with data inconsistencies on top of everything else.
If there’s a problem, the system automatically rolls back in just 400 milliseconds or if there’s an error rate of 1%. Every change to the code made by AI goes through a review process before it’s released. The team that oversees the system’s reliability has the ability to manually override it if needed when traffic is being redirected. A dashboard tracks the health of the migration in real time, showing which modules have been migrated, how much debt has been reduced, and the quality of the code.
Key differentiator: Dual-write synchronization throughout cloud migration — data integrity maintained continuously, not just at cutover
3. IBM
Website: ibm.com
Location: 170+ countries
Founded: 1911
Here’s how IBM approaches moving to the cloud – it’s not about replacing what they have, but about making things work together. They have a system called IBM Z & Cloud Modernization Stack that lets companies use their mainframe capabilities with newer cloud-based apps through APIs, all while still using z/OS for important tasks. The move to the cloud happens step by step, with specific tasks being moved when they’re ready, rather than all at once. For companies that are already heavily invested in IBM’s infrastructure, their integration with Red Hat OpenShift provides a way to move to the cloud without having to start from scratch.
Key differentiator: Mainframe-to-cloud coexistence model — migration happens in parallel with ongoing mainframe operations, not after them
4. Kyndryl
Website: kyndryl.com
Location: 66 countries
Founded: 2021
Team size: 80,000
Kyndryl’s approach to cloud migration is flexible – they consider several options, including moving everything to the cloud, updating the existing system to work with the cloud, or a combination of both. This means they choose the best path based on what the workload actually needs, rather than following a one-size-fits-all method. Their tool, Kyndryl Bridge AIOps, helps them keep an eye on things during the tricky part of the migration process, when both the old and new systems are running at the same time. This is usually the riskiest part of the whole process. With Kyndryl’s platform, they can see what’s happening in real-time across both environments, which helps them spot problems and fix them quickly.
Key differentiator: Multi-path cloud migration with AIOps visibility during the highest-risk parallel-run phase
5. Accenture
Website: accenture.com
Location: Global
Founded: 1989
When it comes to moving to the cloud, Accenture’s expertise starts long before any money is spent. They help determine which mainframe workloads should move to the cloud, which are better off staying put, and which are no longer needed at all. Making the wrong call leads to a familiar problem: spending years moving technical debt to cloud infrastructure instead of eliminating it. Their partnerships with AWS, Microsoft, and Google give them leverage to negotiate better outcomes regardless of which cloud target the organization chooses.
Key differentiator: Mainframe portfolio rationalization before cloud migration — determines what moves before committing execution resources
6. Wipro
Website: wipro.com
Location: India (global)
Founded: 1945
Team size: 250,000+
Wipro makes sure to include Continuous Integration and Continuous Deployment right from the beginning when moving mainframe workloads to the cloud. This means the outcome is not just a mainframe workload that has been shifted to the cloud, but a system that is actually easier to modify and manage in the cloud than it was on the mainframe. This is especially important for industries like banking, telecom, and retail, where there are strict rules to follow. Wipro’s approach ensures that compliance is taken care of throughout the entire migration process, rather than just checking at the end.
Key differentiator: CI/CD and compliance governance embedded throughout cloud migration — not validated at the end
7. Astadia
Website: astadia.com
Location: United States
Founded: 2002
Team size: 350
Astadia specializes in mainframe-to-cloud migration — it’s their core focus, not a side service. Their FastTrack methodology transforms mainframe applications into something that can genuinely run in the cloud, not just get moved there. GenAI-assisted code conversion handles the transformation at scale. Their AWS partnership is a direct one — commercial and technical access that generalist providers simply don’t have.
Key differentiator: Specialist mainframe-to-cloud migration with GenAI-assisted conversion and direct AWS partnership
How to Choose Mainframe Modernization Companies for Cloud Migration
Start with workload assessment, not cloud selection
When it comes to moving to the cloud, what really matters is not the end goal, but rather which tasks are being moved and in what sequence. It’s essential to ask cloud providers about their process for evaluating mainframe workloads to determine if they’re ready for the cloud. Specifically, you want to know what criteria they use to decide whether a workload can be simply lifted and shifted to the cloud, or if it needs to be refactored first, or if it’s better left on the mainframe. If a provider glosses over this step and jumps straight into designing a cloud architecture, they’re likely setting themselves up for a costly surprise down the line.
Ask about parallel operation during migration
When you’re moving your mainframe to the cloud, there’s a really tricky part – it’s when both the old and new systems are running at the same time. This is the most critical phase of the whole process. You need to know exactly how long this parallel phase will last, how you’ll keep an eye on both systems, what will make you switch completely to the new system, and what will make you go back to the old one if things don’t work out. Don’t accept vague responses about managing risk — you need clear, specific details about what thresholds will trigger certain actions and what mechanisms are in place.
Evaluate data synchronization approach
When moving data from a mainframe to the cloud, one of the biggest challenges is making sure everything stays consistent. This is where a lot of migration projects run into trouble. So, it’s crucial to ask your provider how they plan to keep your data in sync throughout the entire process – not just when you’re making the final switch. You want to know if they use a dual-write approach and if they have checks in place to ensure data integrity while both systems are running in parallel.
Check cloud partnership depth
When a company says it’s partnered with a cloud provider, it doesn’t necessarily mean they have a close, working relationship. You need to dig deeper and ask about the specifics of their partnership — do they get special engineering support, do they work together to sell their products, and can they tap into the cloud provider’s technical expertise? For AWS or Azure-target programs, the level of support they get can make a big difference in what they can actually accomplish.
Require migration-specific compliance experience
Cloud migration from mainframe in regulated industries carries compliance requirements that apply to the migration process itself. Data residency, audit trail requirements, regulatory reporting during parallel operation — verify that providers have handled these specifically in your regulatory environment.
For a broader comparison of mainframe modernization companies for cloud migration, Recode lets you search and compare vendors across software modernization, application migration, and legacy transformation.
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About the Author:
Meet Angela Daniel, an esteemed cybersecurity expert and the Associate Editor at SecureBlitz. With a profound understanding of the digital security landscape, Angela is dedicated to sharing her wealth of knowledge with readers. Her insightful articles delve into the intricacies of cybersecurity, offering a beacon of understanding in the ever-evolving realm of online safety.
Angela's expertise is grounded in a passion for staying at the forefront of emerging threats and protective measures. Her commitment to empowering individuals and organizations with the tools and insights to safeguard their digital presence is unwavering.
