What is the difference between microservices architecture and monolithic architecture?

The main difference in application decomposition.

Monolithic architecture:

• A single, self-contained executable file.
• All components (UI, business logic, data access) are tightly coupled.
• Scaling occurs by cloning or scaling the entire application.

Microservices architecture:

• The application is divided into a set of small, autonomous services, each performing its own function.
• Services interact with each other over the network, usually via API.
• Each service can be deployed, scaled, and developed independently.
• Services can use different technologies and programming languages.

Key differences:

Attribute	Monolith	Microservices
Size/Structure	Large, single block	Set of small, independent services
Dependencies	High	Low, via API
Deployment	One-time deployment of the entire app	Independent deployment of services
Scaling	Vertical (server capacity) or horizontal (cloning)	Horizontal, by services
Technologies	Usually one technology/language	Possible to use different technologies
Fault Tolerance	Failure in one component can crash everything	Failure of one service affects less
Development	Slow, teams work on the entire codebase	Fast, teams work on services independently
Complexity	Less at the initial stage	Greater due to distributed system