Key Differences Between SOA and Microservices

Key Differences Between SOA and Microservices:

Aspect	SOA (Service-Oriented Architecture)	Microservices
Granularity	Coarse-grained: services cover large business functions.	Fine-grained: services focus on a single responsibility.
Communication	Often via ESB (Enterprise Service Bus), SOAP, XML.	Lightweight protocols: REST, gRPC, event-driven (Kafka, RabbitMQ).
Coupling	Tends to be more coupled; services share schemas and dependencies.	Loosely coupled; each service is autonomous.
Data management	Typically shares a common database.	Each service owns its own database.
Technology stack	Usually homogeneous across the enterprise.	Heterogeneous; each team can choose the best stack.
Governance	Centralized with strict standards.	Decentralized, team autonomy.
Scalability	Scales by entire service layers.	Scales independently per microservice.
Deployment	Heavy, coordinated releases.	Lightweight, independent deployments with CI/CD.
Reuse	Strong focus on reuse across the enterprise.	Focus on independence rather than reuse.
Typical use case	Enterprise systems integration, legacy modernization.	Cloud-native apps: Netflix, Uber, Amazon.