AI-assisted modernization matters most when the systems at stake are the ones the business cannot afford to get wrong.

In healthcare, financial services and energy, modernization is not just a migration problem. It is a control problem. Core claims platforms, payment engines, batch feeds, reporting systems and operational applications still run critical parts of the business. They also contain years of embedded business logic, regulatory interpretation and operational exceptions that are often poorly documented, tightly coupled and difficult to trace. Every change must preserve continuity. Every release must stand up to scrutiny. And every modernization decision must be explainable to engineering leaders, risk teams and auditors alike.

Publicis Sapient helps organizations modernize critical systems with Sapient Slingshot, our AI-powered software development and modernization platform. Rather than jumping directly from old code to new code, Slingshot helps teams understand what legacy systems actually do before transformation begins. It extracts hidden business logic, turns it into verified specifications, improves testing and maintains traceability across delivery so modernization can move faster without losing control.

Why modernization is harder in regulated industries

Legacy systems often encode the rules behind claims adjudication, payment processing, eligibility, reconciliation, reporting and plant operations. Those rules may live across COBOL programs, copybooks, batch jobs, outdated applications and manual workarounds built up over decades. Documentation is often incomplete or missing. The people who understood the original logic may be retired, hard to access or stretched across too many priorities.

This is why modernization so often stalls. Teams are not simply moving applications to a new environment. They are trying to preserve business behavior they cannot fully see.

In healthcare, that can affect claims accuracy, service continuity and patient or member outcomes. In financial services, it can affect payments, data products, reporting and trust. In energy, it can affect operational resilience, safety, compliance and the ability to maintain critical applications that the business still depends on every day.

For leaders in these sectors, faster code generation alone is not the answer. The real requirement is safer modernization with proof.

Modernization is a control strategy

Traditional modernization efforts often rely on manual reverse engineering, incomplete requirements and scarce SME knowledge. That approach creates delays, but it also creates risk. Hidden dependencies surface late. Critical rules are inferred instead of verified. Testing becomes a bottleneck. Evidence for governance and audit gets reconstructed near release rather than generated throughout the work.

This is where Sapient Slingshot changes the equation. Slingshot inserts a specification layer between the legacy estate and the future-state platform. It reads legacy code, extracts business rules and dependencies, and converts that knowledge into structured, reviewable specifications. Those specifications become a clearer source of truth for what the modernized system must preserve.

That matters because regulated modernization is not successful when code simply compiles in a new language or runs in a new environment. It is successful when business-critical behavior remains intact, delivery evidence is traceable and change can be defended with confidence.

How Sapient Slingshot helps teams modernize with greater control

Verified specifications from legacy code

Slingshot helps recover business intent directly from the system. Rules that were once buried in code become visible, testable and reviewable by engineers, architects and business stakeholders. This reduces dependence on tribal knowledge and gives teams a stronger basis for future-state design.

Dependency mapping before major change

Modernization in regulated environments becomes dangerous when interconnections are poorly understood. Slingshot helps surface dependencies across programs, services and data flows so teams can sequence work more safely, identify downstream impact earlier and avoid avoidable disruption.

Stronger testing and validation

In high-stakes systems, “close enough” is not acceptable. Slingshot improves test generation and quality automation so validation keeps pace with delivery. By tying tests back to specifications and original behavior, teams can better prove that the modernized system behaves as intended.

Traceability across the lifecycle

Auditability should not be a late-stage exercise. Slingshot helps maintain continuity from legacy code to specification, from specification to design, and from design to modern code and testing artifacts. That creates a more connected evidence trail for stakeholders who need visibility into what changed, why it changed and how it was validated.

Humans in control throughout delivery

AI accelerates analysis, documentation, transformation and testing, but people remain accountable. Publicis Sapient keeps engineers, architects and business stakeholders in control at the points that matter most. Outputs are reviewed, refined and validated before they move forward. This is not black-box automation. It is governed acceleration.

What this looks like in practice

In healthcare, Publicis Sapient helped a leading U.S. health care benefits provider modernize more than 10,000 COBOL and Synon mainframe screens that were slowing claims processing and customer service. Using Slingshot, hidden business rules and dependencies were surfaced, functional artifacts and tests were generated, and migration moved 3x faster while reducing modernization costs and supporting a safer move toward a cloud-native environment.

In financial services, Publicis Sapient worked with a major retail and commercial bank to analyze highly complex legacy programs supporting core financial and payments-related services. In eight weeks, teams analyzed hundreds of files and nearly half a million lines of code, producing structured specifications, flowcharts, field mappings and execution-ready artifacts. The engagement reduced manual code-to-spec effort by 70 to 85 percent, reached 95 percent accuracy in generated specifications and increased migration speed by 40 to 50 percent. More importantly, it made buried complexity more visible and auditable before major code changes began.

In energy, Publicis Sapient helped RWE recover and modernize a decades-old application with no accessible source code or documentation. With Slingshot and human oversight, the application was revived in two days, business logic was surfaced and documentation was generated for future maintainability. The result was not just speed, but a meaningful reduction in black-box operational risk.

These examples point to the same lesson: in regulated environments, modernization works best when AI is used to improve system understanding, validation and governance, not just to generate code faster.

Why this matters for healthcare, financial services and energy leaders

If continuity, compliance and auditability are non-negotiable, modernization cannot be approached as a speculative rewrite or a simple migration factory. It has to preserve what the business depends on while making future change easier, safer and more measurable.

That means turning hidden logic into verified specifications. It means mapping dependencies before disruption occurs. It means improving testing so teams can validate behavior continuously. And it means keeping humans in control so accountability remains where it belongs.

Publicis Sapient brings those disciplines together with Sapient Slingshot to help organizations modernize critical systems with stronger proof, not just more speed.

Modernize critical systems without losing control

For regulated enterprises, the question is no longer whether modernization can wait. It is whether modernization can happen without introducing new uncertainty.

With Sapient Slingshot, Publicis Sapient helps organizations move from opaque legacy estates to explainable, maintainable and traceable modern platforms. By extracting business logic into verified specifications, strengthening testing, preserving traceability and keeping human oversight embedded throughout delivery, we help clients modernize with the control that regulated environments demand.

Because when the systems at stake are too important to guess at, modernization should deliver more than faster migration. It should deliver confidence.