Digital Core Modernization

Many organizations today find themselves managing applications developed years ago, often critical to the business but difficult to evolve. 

Among the most common challenges: 

• increased maintenance costs 
• difficulty integrating with new technologies 
• slow release cycles 
• reliance on obsolete architectures 
• difficulty ensuring security and compliance 
• need to integrate AI systems 
  
  
  Continuing to maintain legacy systems without evolving them can limit innovation capacity and increase operational risk. 
  
  According to the Digital Innovation Observatory of Politecnico di Milano, 39% of the application portfolio of large Italian companies today requires modernization. (Digital Innovation Observatories, PoliMi, 2025, based on a sample of 69 large Italian companies). This data makes modernization not a long-term strategic option, but an immediate execution priority.

Agentic Coding, where people define the intent, architecture and acceptance criteria, and agents plan and write the code is transforming the way legacy application modernization is tackled. adesso.it has been applying it since the Discovery phase, where it analyzes code even in the absence of updated documentation or available original skills, reconstructing the functional map of existing systems. 

In the Rewriting phase, Agentic Coding supports the translation and automatic code generation and produces live documentation, consultable in natural language by developers and stakeholders. 

Dependency analysis assisted by Agentic Coding identifies the most effective bounded contexts for the transition to microservices architecture, favoring autonomy and decoupling between teams. 

The Agentic AI is shifting the balance of make-or-buy choices in application modernization, reducing investments, times, and risks to the point of making it feasible even where in the past the cost would have leaned towards a packaged solution while maintaining customization space and data control. This is evident in concrete cases followed by adesso.it: from the replacement of an e-learning SaaS platform with a custom solution developed by a small team alongside AI agents to the modernization of a mobile banking platform migrated from a Java EE monolith to microservices Spring Boot and Kafka on Kubernetes, up to the transformation of a B2B/B2C e-commerce platform with over three million lines of code. 

adesso.it integrates Agentic Coding into its application modernization projects with the same rigor of governance, quality, and operational continuity described on this page. 

For further exploration, please refer to this article.

Depending on the needs to be addressed, an application modernization project can address three complementary dimensions, often activated in combination to ensure lasting results. 

1. Infrastructure Modernization 

Updating the infrastructure towards cloud or hybrid environments, with objectives of improved scalability and security, reduced operational costs, and lower vendor dependency. 

2. Architectural Modernization 

Redesigning the application architecture towards cloud-native paradigms to achieve more usable, evolvable, and scalable applications over time. 

3. Functional Evolution (full transformation) 

Extension and redesign of application functionalities to support the business in market competition with a modern and future-ready application.

An application modernization path cannot ignore a solid, measurable, and transparent governance from day zero. adesso.it tackles this challenge by defining KPI values from the setup phase that allow management to make informed decisions based on real and always available data. The metrics system adopted by adesso.it is articulated on five dimensions: Business & Value Metrics for visibility on generated value, Flow Metrics for identifying bottlenecks in delivery, Predictability Metrics to reduce uncertainty and align stakeholder expectations, Quality Product Metrics to monitor product stability, and System Health Metrics to prevent downtime and production environment degradations. This approach enables companies to transform application modernization from an opaque project into a measurable investment with verifiable returns sprint after sprint. 

The initial setup is a crucial phase: it defines the KPI values that enable informed decisions, based on transparent and always available information.

One of the most common and costly mistakes in application modernization projects is the “Big Bang” approach: the complete replacement of the legacy system in a single solution. adesso.it considers this approach excessively risky for core business applications, as it exposes the organization to operational disruptions that are difficult to accept. The working method of adesso.it to ensure business continuity during modernization is based on two complementary principles: the progressive and incremental migration of application components, and the parallel management of the legacy system and the new solution during transition phases. As the guiding principle of adesso.it states, it is about “changing the engine on the plane in flight”: the most serious failures in modernization projects almost always stem from wrong or underestimated technological choices in managing operational continuity. 

*Note: in the figure next to it, one of the approaches of *adesso.it is described for ensuring business continuity. The approach is adaptive to the specific case and depends on the client’s peculiar context. In the represented infographic, a method is described to guarantee coexistence between legacy (monolithic core system) and new (microservices architecture), with a virtualization layer above the legacy database.

Application modernization generates real value only if the business is an active part of the decision-making process, rather than just an external client. adesso.it adopts an agile and iterative approach to priority management, allowing tangible results to be produced from the first iteration, avoiding the limitations of fixed scope typical of waterfall models. 

Updating and maintaining the backlog, continuous monitoring of business KPIs and an iterative project pipeline allow priority to be adjusted based on contextual changes that grow exponentially over time in any modernization path. 

Co-design with the client is not a methodological option: for adesso.it it is the necessary condition to transform modernization into an engine for generating competitive value.

In application modernization projects involving mixed teams, with supplier resources and client internal resources collaborating on the same product, knowledge management is a critical variable often underestimated. adesso.it structures the sharing and dissemination of knowledge through four systemic mechanisms: agile events (planning, review, retrospective) as moments of continuous alignment; cross-team Community of Practice to ensure architectural solution uniformity among different teams; multi-team clarification sessions for scaled contexts; and a Whole Product Focus approach that prevents team verticalization on single areas, promoting an integrated vision of the product. This way, knowledge does not remain the supplier's heritage but becomes firmly rooted in the client's organization. 

A concrete example of this approach is described in this application modernization case study for Alpitour World

Scaling an application modernization program across multiple teams without losing coherence, speed, and quality is one of the most complex organizational challenges a CIO faces. The model of adesso.it involves multidisciplinary teams with all necessary skills, both technical and functional, operating in a coordinated manner through a single shared backlog and synchronized events of planning, clarification, and retrospectives. On a technological level, the enablers selected by adesso.it ensure that each team can work autonomously within its domain without introducing blocking dependencies. Organizationally, the Whole Product Focused model ensures that each team maintains a comprehensive product vision, reducing the risk of local optimizations that penalize the global quality of the system.

Technological and architectural choices in a modernization project are not solely based on technical factors: they result from a multidimensional analysis that adesso.it conducts considering available budget and resources, the client's internal competencies, existing architectural roadmap, technologies already present in the company, time constraints, and business goals. Regardless of the specific context, adesso.it applies three invariant architectural principles: the adoption of modern paradigms like microservices, modular monoliths, or agent-based architectures chosen based on objectives; the implementation of CI/CD pipelines to ensure speed, quality, and reliability in the release of new features; and an Observability strategy that ensures constant monitoring and traceability of applications to prevent degradation and guarantee the ability to act quickly in production. 

Software quality is not a result achieved at the end of the project: it is a property that is systematically built along the entire modernization journey. adesso.it ensures product quality through an integrated set of engineering practices, principles, and design patterns, continuous integration, continuous refactoring and active management of technical debt, test automation, code quality metrics, security by design, and observability, which converge in the production of verifiable quality code. This approach translates into concrete and measurable benefits for the business: increased speed and automation in the release, guaranteed business continuity, functional scalability, compliance, and security by design, structured data management, and organic spread of technical knowledge within the client organization.

Application modernization with Agentic coding is a strategic lever to ensure operational continuity and support business evolution. It reduces maintenance costs related to accumulated technical debt and vendor dependence by updating to cloud or hybrid environments. It shortens release cycles through CI/CD pipelines, test automation, and decoupled architectures, allowing for quicker responses to market changes. It makes applications more robust in the face of increasing regulations and risks thanks to security by design and structured observability. It is also an attractiveness factor for talent, as working on modern architectures integrated with Agentic AI makes teams more capable of attracting and retaining skills. Finally, it is a fundamental enabler for the integration of new technologies, allowing one to fully grasp the benefits offered by solutions based on Agentic AI and GenAI.