How does the concept of a distributed monolith arise in system architecture?

A distributed monolith occurs when a system is divided into several services or components, but architecturally and organizationally they are tightly coupled and dependent on each other, leading to the following problems:

• Services cannot evolve and deploy independently, as changes in one require changes in others.
• A shared database or synchronous calls between services create strong dependencies.
• Lack of clear responsibility boundaries and weak cohesion.

Reasons for occurrence:

• Attempting to break down a monolith without revisiting the architecture and business logic.
• Lack of maturity in microservices design.
• Organizational constraints when teams are not divided by services.

Ultimately, a distributed monolith is an anti-pattern that appears as a microservices architecture but essentially retains all the disadvantages of a monolith, complicating support and scaling.