Legacy modernization for regulated industries

In regulated industries, legacy modernization is never just a technology exercise. It is a change to systems that often sit at the center of claims processing, core banking, policy administration, billing, settlements and operational workflows the business cannot afford to interrupt. These environments demand more than speed. They demand evidence, control and continuity.

Rather than moving directly from old code to new code, Slingshot helps enterprises first understand what the legacy system actually does. It extracts buried business rules, maps dependencies, documents system behavior and generates reviewable specifications before transformation begins. Those specifications become the source of truth for design, code generation, testing and validation. The result is a modernization path built for organizations that need to modernize mission-critical systems without losing auditability or control.

Why regulated environments need more than code conversion

Traditional modernization tools often focus on conversion speed alone. But in healthcare, financial services, insurance, energy and utilities, direct code conversion is rarely enough.

Critical business logic is often spread across decades-old code, batch jobs, interfaces and undocumented workflows. Rules may reflect years of policy updates, customer exceptions, operational safeguards and regulatory obligations. When teams modernize based on assumptions instead of verified understanding, they increase the risk of rework, missed dependencies, weak auditability and production disruption.

Modernization has to make legacy behavior visible before change begins. It has to preserve traceability from source to specification to generated assets. It has to support stronger testing, parity validation and reconciliation. And it has to keep people in control at the moments that matter most.

A specification-led path from legacy to modern

Sapient Slingshot is designed to help enterprises modernize with greater fidelity and lower risk through a connected workflow.

1. Understand the current system before changing it

The first step is to make the legacy estate explainable. Slingshot analyzes existing applications to extract business rules, map application logic, trace data relationships and uncover dependencies and workflows that may never have been fully documented. It can generate structured specifications and testable scenarios from real system behavior, giving architects, engineers, product owners and business stakeholders a clearer shared view of what must be preserved.

For regulated programs, that foundation matters. It reduces dependence on tribal knowledge and scarce specialists while creating reviewable artifacts that support inspection, validation and alignment.

2. Transform from a verified source of truth

Once business intent has been captured in specifications, Slingshot helps carry that context into the target state. Instead of generating modern code from guesswork or isolated prompts, it uses reviewable specifications to guide architecture, code, tests and data outputs.

This specification-led model helps reduce ambiguity and improve validation. It also maintains traceability between legacy source, specifications and generated assets, making it easier to show how critical functionality was carried forward.

3. Deploy with validation, reconciliation and fallback paths

Modernization does not end when code is generated. In compliance-sensitive environments, the final stages are often where confidence is won or lost.

Slingshot supports parity validation and reconciliation to compare legacy and modernized outputs before release. Teams can use dual-run approaches, plan rollback paths and execute progressive cutovers to reduce disruption risk. That production-safe change model is especially important where resilience and continuity are non-negotiable.

Built for reviewability, traceability and human oversight

Slingshot is designed to produce more than code. Across the modernization lifecycle, it can generate specifications, process flows, mappings, dependency views, architecture artifacts, backlog items, user stories, documentation and test assets alongside deployable modern code. These outputs make the work easier to inspect and govern across engineering, architecture, product and compliance stakeholders.

Just as important, Publicis Sapient brings a people-plus-product model to delivery. Slingshot accelerates discovery, analysis, transformation and test generation, while Publicis Sapient experts guide architecture, delivery and governance. Human review remains built in at critical gates so teams can validate business logic, assess risk, confirm production readiness and keep accountability where it belongs.

Stronger testing and clearer evidence throughout delivery

Many modernization programs speed up during analysis and build, only to stall when testing becomes the next bottleneck. In regulated industries, testing is about more than defect reduction. It is about validating behavioral equivalence, proving that critical rules were preserved and building the evidence needed for release decisions.

Slingshot supports automated test generation and quality workflows so validation can keep pace with modernization. By linking specifications, generated code and test assets in one connected flow, it helps teams move toward deployment with stronger coverage, clearer evidence and less manual translation between stages.

The platform’s enterprise context graph also helps ground AI outputs in the real enterprise environment by maintaining a living map of logic, data, dependencies and workflows. That continuity reduces context loss across backlog, planning, development, testing and deployment.

Proven in high-stakes modernization programs

Publicis Sapient’s approach is already backed by proof points in compliance-sensitive and operationally critical environments.

In healthcare, Publicis Sapient modernized legacy COBOL applications used for claims processing for a U.S. healthcare organization into cloud-native systems, accelerating migration by 3x and reducing estimated costs by more than 50%.

In banking, Publicis Sapient analyzed nearly 3 million lines of COBOL for a global bank’s core banking system, achieving 95% specification accuracy, reducing analysis time per feed from 35 days to 5 days, cutting code-to-spec effort by up to 85% and generating more than 200 implementation-ready backlog items.

In energy, Publicis Sapient helped modernize a 24-year-old Java-based customer application for RWE in two days, achieving 35–45% time savings in code generation, improving test efficiency by 40% and creating a more maintainable, reusable application.

These examples show what matters most in regulated modernization: faster progress without sacrificing explainability, fidelity or control.

A fit for modernization programs where continuity cannot break

Sapient Slingshot is designed for large, complex and business-critical estates across mainframe, custom applications, data platforms, front-end systems, desktop applications and broader enterprise platforms. It is especially relevant where modernization must preserve operational continuity, support auditability and reduce dependence on shrinking pools of legacy expertise.

For organizations modernizing claims, core banking, policy, billing and operational systems, the question is not whether AI can generate code quickly. The real question is whether modernization can be made reviewable, traceable and safe enough for the business to trust.

Publicis Sapient’s answer is a specification-led model that starts with understanding, carries business intent forward and validates change before it reaches production.

Modernize what matters most without losing control

When the systems at stake are mission-critical, modernization needs more than conversion. It needs business-rule extraction, reviewable specifications, source-to-output traceability, stronger testing, parity validation and human oversight at the gates that matter.

With Sapient Slingshot and Publicis Sapient’s modernization expertise, regulated enterprises can move faster while preserving the controls, resilience and continuity their businesses depend on.

Begin with a focused 4–6-week engagement to assess modernization feasibility, evaluate Slingshot in your environment and define a clear path to scale.