Disadvantages of a monolith include:
Slower development speed – A large, monolithic application makes development more complex and slower.
Scalability – You can’t scale individual components.
Reliability – If there’s an error in any module, it could affect the entire application’s availability.
Barrier to technology adoption – Any changes in the framework or language affects the entire application, making changes often expensive and time-consuming.
Lack of flexibility – A monolith is constrained by the technologies already used in the monolith.
Deployment – A small change to a monolithic application requires the redeployment of the entire monolith.