Case Study: Monolith-to-Microservices Migration

Migrating from a monolithic application to microservices is one of the most common real-world architecture challenges. Many companies begin with a monolith because it's simple to develop, deploy, and operate. A small team can build the application, maintain a single codebase, and use one database for most business operations.

As the company grows, however, the monolith may become harder to manage. Different teams need independent release schedules. Some features require significantly more computing resources than others. Changes in one part of the application can unexpectedly break unrelated functionality.

At this point, organizations may consider migrating to microservices. But migrating a running production system is very different from designing a new microservices architecture. You must preserve existing functionality, maintain data consistency, avoid disrupting customers, and gradually replace parts of the application without introducing unnecessary risk.

In this chapter, we'll walk through a realistic migration case study, examining the architectural decisions, implementation strategy, and challenges involved.