How to Prepare Your Tech Stack for Agentic AI

As businesses scramble to unlock the power of agentic AI, the same systems demanding modernization can also streamline it.

Written by Sriram Devanathan
Published on Jul. 14, 2026
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Summary: Enterprise modernization has shifted from a “should” to an urgent business “must” driven by agentic AI. While legacy systems like COBOL mainframes cannot directly support AI agents, specialized AI agents are now speeding up modernization, allowing companies to cut technical debt and costs by up to 80 percent.

For decades, enterprise modernization sat on the “should” list. Companies should modernize because it cut costs, sped up innovation and reduced technical debt — a problem that now costs an estimated 1.5 trillion dollars in the United States alone. 

Now, the word I keep hearing from enterprise leaders is not “should.” It’s “must.” A customer told me she must modernize a system in two years. No ifs, no buts. In the past, that project would’ve taken an estimated six or seven years. Today, it’s a business imperative. 

That shift, from we should modernize to we must modernize, is propelled by agentic AI.

Why Is Enterprise Modernization a Business Imperative?

Enterprise modernization has shifted from a should to a must because legacy systems (like decades-old COBOL mainframes) cannot directly support modern AI agents. To unlock the value of agentic AI, companies must modernize their core systems and data structures. By using specialized AI agents instead of traditional rule-based tools, organizations can now bypass multi-year timelines and safely compress migration and modernization into a single step, reducing project times and technical debt by up to 80 percent.

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Legacy Code Cannot Compete

Before agentic AI, modernization took years. Companies needed to hire the right people, and if a system was built 30 or 40 years ago, finding an engineer who knew that variant of COBOL was nearly impossible. 

Organizations had time and expertise problems. Rule-based tools existed, but these tools could only tackle the limited cases that they were designed to handle. Every edge case, every nook of a complex legacy system, required human judgment and specialized knowledge that was becoming harder and harder to find.

These projects exceeded budgets and stretched for years, which meant modernization efforts stalled before they delivered any value. Companies would run pilots, find themselves unhappy with the ROI and shelve the project. But the backlog of technical debt kept growing.

 

The Agentic AI Paradox

Agentic AI is both the reason companies must modernize and the tool that makes modernization possible at a speed we’ve never seen before. 

As more companies race to bring AI agents to their customers, those agents need to interact with the customers’ core systems. But many of those systems were built with technologies from decades ago, and you can’t just bolt an AI agent onto a COBOL mainframe and call it a day. It’s not that simple.

We can only see the value of agentic AI when it can use companies’ data and core systems reliably. Modernization has gone from a worthy goal to a prerequisite.

The new generation of transformation tools encode deep migration and modernization expertise into agents that can assess systems, map relationships between components, perform dependency analysis, decompose monoliths into cloud-native structures and validate output end to end. Because these agents can reason and generalize, they’re able to handle the complex corner cases that rule-based systems never could. 

The traditional approach was to migrate, then modernize. It seemed less risky to take it in several stages. But companies are telling us more and more that they want to transform legacy systems in one step, not two. 

Using AWS Transform, an agentic service that I helped build, Thomson Reuters has reduced its tech debt by 50 percent and cut costs by 30 percent. Air Canada used the service to upgrade its Node.js runtimes in a matter of days, with a 90 percent efficacy rate and overall project time and cost dropping by roughly 80 percent. The flexibility of agentic systems makes that possible.

 

A Team of Agents That Know When to Ask for Help

What makes agentic transformation work is that there isn’t one agent doing everything. It’s multiple specialized agents collaborating in real time with humans-in-the-loop at important checkpoints. Each transformation includes built‑in validation criteria, including tests and guardrails like which libraries can be included or excluded based on company policy. Companies can layer in their own validators that run on top of transformed code so all outputs meet specific security and compliance standards.

For mainframe modernization, the system extracts COBOL logic into a set of documented business rules, then traces each function in the new code back to its source rule, so you get full traceability. That approach is a best practice in engineering, and it’s how you maintain security and compliance when you are touching mission-critical systems.

Consider a bank that processes millions of mortgage payments through a decades-old COBOL application. The system extracts the business rules — interest accrual, escrow allocation, late-fee logic — directly from the execution logic, with each rule traced to exact source code lines. When those rules become requirements for the modern application, the traceability chain remains intact and if a regulator asks why a payment was processed a certain way, the team can follow that chain end to end.

On the privacy side, the best transformation platforms enforce strict data boundaries by design. Enterprise data should be encrypted, never shared or used to train new models, and for the most sensitive workloads, organizations should be able to run transformations entirely within their own environments. Code and tests never leave internal systems while the agents still do the heavy lifting.

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Migration and Modernization in an Agentic World

The companies that move the fastest are treating migration and modernization as a continuous process, not a one-time event. AI agents are now embedded at every layer, scanning repositories at scale, surfacing end-of-life dependencies and deprecated frameworks, and generating fixes for teams to review and merge.

In the past, new technology operated at a much slower pace, and most organizations could afford to adopt it gradually. Agentic AI does not offer that luxury. Companies are already expecting smarter, more responsive systems, and those expectations rest on how quickly you can bring your core applications into the modern world. 

Migration and modernization can no longer sit in the backlog. They’re what make it possible to bring agentic AI into the heart of your business.

Hyperlinks in the article were added by the Built In team.

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