Why was the monolith split into microservices?

Splitting a monolith into microservices usually occurs to improve scalability, flexibility, and manageability of the system. In a monolith, all components are tightly coupled, which makes it difficult to make changes and scale individual parts. Microservices allow:

• Dividing the system into independent services that can be deployed and scaled separately.
• Using different technologies and databases for different services.
• Simplifying support and development, as teams can work on individual services independently.
• Increasing fault tolerance: a failure of one service does not lead to the failure of the entire system.

For example, in an online store, separate microservices can be allocated for the product catalog, cart, payment, and notifications, which will allow faster development and scaling of each of them.