Service-Oriented Architecture (SOA)

Summary

Reusable, contract-driven services integrated via mediation (often ESBs) with centralized governance; a precursor to microservices.

What it is

An architectural style organizing capabilities as interoperable services with well-defined contracts, often mediated by an ESB for routing, transformation, and policy.

Benefits

• Promotes reuse and consistent contracts
• Centralized policy and visibility
• Good fit for heterogeneous enterprise landscapes

Trade-offs

• Risk of central ESB becoming a bottleneck
• Tighter coupling via shared schemas and governance
• Slower change velocity vs. decentralized approaches

When to use

• Large enterprises with many legacy systems
• Strong need for standardization and mediation
• Gradual modernization toward microservices