Challenges of Monolithic Systems Modernization

2024-07-09

Upgrading legacy systems is an expensive and time-consuming endeavour that affects most of the Hungarian Financial Institutions. Advocate Business Consulting’s experts were leading many feasibility workshops in the past couple of months that helped CIOs initiate large-scale core system modernization projects and with the help of our experts those projects were carried out successfully by utilizing some already well-established core principles.

Modernizing monolithic core systems using microservices and APIs has become a popular strategy for organizations seeking to improve agility, scalability and innovation. The process involves breaking down large, monolithic applications into smaller, independent and loosely coupled services that can communicate via APIs. This approach allows organizations to incrementally update and modernize specific components without having to overhaul the entire system and perform a risky bing-bang type deployment.

Advocate Business Consulting experts identified three major obstacles and bottlenecks during the development projects involving monolithic core systems:

  • 1. Tight Coupling: in monolithic core systems, all components are tightly interconnected, making updates slow and risky.
  • 2. Limited scalability: monoliths scale as a single unit, which can be resource-intensive and inefficient which makes scaling costly.
  • 3. Slow development cycles: adding new features or fixing bugs require the entire application to be recompiled and redeployed which necessitates a full regression test to be performed, leading to slower release cycles.

One of the most common solutions to these problems is a microservice-based architecture which couple with major organization changes could solve the identified problems:

  • Microservice architecture decouples current components, enabling individual services to be updated independently.
  • Microservices allow for horizontal scaling at service level, so scaling could be performed on an individual service level.
  • Microservices enable faster development cycles because cross-functional teams can work on different services in parallel.

In order to be able to transition from a monolithic mode of operation to distributed microservices-based architecture there are some steps and milestones that need to be reached. The first is a solid foundational design which lays out what should be modernized and how. Our experts proposed and designed a step-by-step approach: the key to successfully modernizing monolithic systems is to break them down incrementally, which minimizes risk and allows the organization to maintain operational continuity:

  • 1. Identify the core functionalities of the monolithic application.
  • 2. Prioritize which parts of the application are most suited for early conversion into microservices.
  • 3.Gradually decompose monolithic modules into independent microservices, starting from low-risk parts of the application and moving to more complex or critical functions.

After identifying the first component to be decomposed, some foundational design principles must be utilizied not just during the design but throughout all phases of the software development lifecycle in order to achieve microservice-based architecture:

  • 1. Loose coupling and independence: each microservice should be independently deployable and self-contained, with its own database (or logically separated data) to avoid dependencies on other services.
  • 2. Single responsibility principle: microservices should be small and focused, each serving a single business function.
  • 3. Autonomy and Ownership: each microservice should be owned by a specific team, encouraging a DevOps culture where teams are responsible for the entire lifecycle of the service - development, testing, deployment and maintenance. Teams must be cross-functional, including developers, testers to enable faster, independent releases. This is one of the foundational pillars of the organizational changes necessary for a successful modernization project.

Modernizing monolithic systems with microservices and APIs allows for a more flexible, scalable, and maintainable architecture. However, it is crucial to take an incremental approach and foster a DevOps culture to achieve long-term success. With the help of Advicate Business Consulting’s experts, the Hungarian Financial Institutions were able to carefully plann and leverage microservices and APIs, and could successfully overcome the limitations of legacy monoliths and accelerate innovation.