Which description best captures microservice architecture and its typical pros and cons?

• A. A set of small, independently deployable services with advantages like scalability and resilience, and challenges like distributed complexity and data consistency.
• B. A monolithic design with a single deployable unit.
• C. A service that uses a single database to ensure consistent data across services.
• D. A pattern that eliminates the need for deployment coordination.

Answer: (A)

Microservice architecture treats an application as a suite of small, independently deployable services, each focused on a specific capability and often owning its own data. This setup makes it easier to scale individual parts of the system and to deploy changes without touching the whole app, and it improves resilience because a failure in one service doesn't necessarily bring down others. But it brings distributed complexity—network communication, each service having its own data store, and the need for distributed tracing, testing, and deployment orchestration—plus data consistency challenges, since enforcing a single global transaction across services is hard and you often rely on eventual consistency or saga patterns. The described choice captures this balance, noting both the benefits and the typical drawbacks. The other options don’t fit: a monolithic design packs everything into one unit; using a single shared database across services contradicts the decentralized data model; and saying deployment coordination can be eliminated ignores the real need for coordination in a distributed system.