From Legacy Modernization to Cloud-Native Delivery on AWS

Legacy technology can slow every part of the business: product delivery, customer experience, operational resilience and the ability to respond to change. For many enterprises, the challenge is not simply moving workloads to the cloud. It is modernizing applications, infrastructure and delivery practices together so teams can reduce technical drag and build for what comes next.

Publicis Sapient helps organizations make that shift with an end-to-end approach on AWS that combines cloud migration, DevOps engineering and AI-assisted application modernization. By bringing together cloud transformation strategy, mobilization, build, migration, testing, observability and managed services, we help enterprises move from aging systems and fragmented delivery models to scalable, cloud-native operations designed for speed, quality and resilience.

Modernization is rarely a single initiative. It often starts with legacy applications that are expensive to maintain, difficult to change and dependent on scarce skills. It is then compounded by siloed infrastructure, inconsistent release processes and limited visibility into performance. Publicis Sapient addresses these challenges as one connected transformation journey.

Our approach is grounded in end-to-end digital business transformation across Strategy, Product, Experience, Engineering, and Data & AI. On AWS, that means aligning modernization goals to a practical delivery model that connects business priorities with platform engineering, migration execution, security, automation and ongoing operations.

Successful modernization begins with a clear cloud transformation strategy. Publicis Sapient helps enterprises assess their current estate, define target outcomes and create a roadmap for migration and modernization that is tied to value—not just technology change. We apply AWS migration best practices to support a smoother transition while shaping the cloud foundations needed for long-term agility.

From there, we help clients mobilize the right capabilities to move quickly. This includes foundation setup, database setup, infrastructure planning, FinOps management and secure cloud-native architecture. For organizations that need to accelerate adoption while controlling cost, access to AWS migration funding can help reduce the cost of transition and speed the move to AWS.

Cloud-native delivery requires more than a landing zone. It requires infrastructure that is secure, scalable and built for continuous change. Publicis Sapient works across cloud strategy, build, security and migration to help enterprises create AWS environments that support modern application delivery from day one.

Our cloud infrastructure services are designed to help organizations dismantle legacy silos, improve collaboration and dynamically scale resources as business demands change. Security is embedded across the journey through data security, cloud-native security, security mesh and network security activities, helping enterprises modernize with confidence while reducing operational risk.

Application modernization is often where transformation slows down. Translating old code, understanding legacy logic and rebuilding for modern architectures can be costly and time-consuming. Publicis Sapient uses AI-assisted modernization to make this process significantly faster and more practical.

Sapient Slingshot modernizes legacy systems by turning existing code into verified specifications and generating modern software with full traceability. Built off Bodhi, our enterprise-ready AI platform on AWS, Sapient Slingshot helps accelerate both modernization and the software development lifecycle. Using large language models, contextual knowledge and pre-built prompt libraries—with human intervention built into the process—we can analyze code, generate target-state documentation, transition legacy applications to modern architectures and automate testing activities.

The outputs are practical and usable for engineering teams, not abstract AI artifacts. These include feature summaries, detailed specifications, transformed architecture, test cases, unit tests and automation test scripts. The result is a modernization process with better traceability, stronger software quality and a faster path from legacy analysis to production-ready delivery.

Modernization succeeds when engineering practices evolve alongside the application stack. Publicis Sapient’s DevOps capabilities help enterprises improve speed, quality and reliability through engineering and automation focused on customer value.

We support DevOps engineering maturity assessments and strategy development so organizations can benchmark their current state, define maturity goals and create actionable improvement plans. We help standardize hosting, implement infrastructure as code and configuration management, and build delivery environments that can be provisioned and managed at scale with greater speed and efficiency.

Our DevOps approach also emphasizes continuous integration, deployment and delivery so teams can release at the pace of the business with more agility and confidence. Code management and standardization practices improve governance and developer productivity, while Agile DevSecOps embeds security throughout the software development lifecycle with a shift-left mindset and a zero-trust foundation.

Modern applications need modern quality and operational practices. Publicis Sapient helps organizations automate validation as part of the delivery pipeline, using AI-assisted generation of test cases, unit tests and automation scripts to expand coverage and reduce defects. In Publicis Sapient’s modernization analysis across more than 100 end-to-end experiments, AI-enabled accelerators demonstrated more than 50% reduction in modernization costs, 50% fewer defects with expanded coverage of requirements and test cases, and a 50% increase in migration speed. Actual outcomes vary by client context, but the direction is clear: modernization can move faster with stronger quality built in.

Once applications are running in AWS, full-stack observability becomes essential. Publicis Sapient delivers comprehensive monitoring, logging and alerting, along with reporting and dashboarding that provide meaningful insight into application and infrastructure performance. This helps teams identify issues sooner, improve reliability and continuously optimize performance in production.

For enterprises that want ongoing support after migration, our AWS managed services provide proactive and preventative capabilities that help organizations reduce risk, refine their cloud environments over time and focus internal teams on innovation rather than routine operational overhead.

The goal is not just to relocate workloads. It is to reduce the drag of legacy technology and create a better operating model for growth. Publicis Sapient helps enterprises modernize faster, lower the cost of transformation and improve delivery confidence through traceable outputs and automated engineering practices.

That value shows up in multiple ways: faster migration timelines, reduced modernization cost, improved traceability from legacy code to modern specifications, expanded test coverage, stronger application performance and more resilient cloud operations. In client examples across AWS-related work, Publicis Sapient has helped organizations achieve outcomes such as 3x faster migration in legacy modernization, 20% cost optimization with 75%+ enhanced application performance in cloud transformation, and 50% reductions in DevOps effort alongside improved cost efficiency and shorter infrastructure setup times.

Publicis Sapient brings together deep cloud, engineering and AI expertise to help enterprises move from strategy to execution with less friction. As an AWS Premier Consulting Partner with broad AWS specializations and a large global base of AWS-trained professionals, we combine platform strength with hands-on transformation experience across industries.

What makes the difference is the combination of cloud infrastructure, DevOps and AI-assisted modernization in one connected journey. We do not treat migration, delivery modernization and application transformation as separate workstreams. We integrate them to help enterprises build secure AWS foundations, modernize legacy systems with greater speed and traceability, and establish cloud-native delivery practices that continue to improve over time.

From the first roadmap to managed operations, Publicis Sapient helps turn AWS into a modernization engine—so legacy technology stops holding the business back, and cloud-native delivery starts creating measurable momentum.

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