Microservices

The term “microservice” is widely discussed and often referred to as a buzzword in the technology industry.
Microservices are popular due to their scalability, extensibility, and resilience when implemented correctly.
The conversation aims to address common challenges and best practices for effective use of microservices.

A favored definition: a microservice is an independently deployable unit focused on performing a single job very well, communicating via clearly defined interfaces.
Successful microservice design emphasizes complete independence between components.
Needing to deploy multiple services together frequently suggests incorrect service boundaries or unnecessary coupling.

Communication between microservices must strictly occur through well-defined interfaces; direct access to another service’s data or memory is not allowed.
Following Jeff Bezos’s API mandate: no direct linking, data store reads, shared memory, or backdoors; only service interface calls over the network.
Interface forms may include API calls, message passing, or event-driven mechanisms, but must always maintain clear contracts or schemas.
It is crucial to never break backwards compatibility for these interfaces.

Properly implemented microservices foster flexibility—allowing independent team work and rapid, low-risk feature releases.
Ideally, if one microservice fails, others continue functioning without interruption.
Service failures should not cascade to impact high-value or unrelated services.
Building in patterns to manage cascading failures and resilience is necessary at scale; detailed guidance will follow in later modules.

The high-level microservices overview invites deeper exploration into their detailed implementation.
Emphasis on thoughtful adoption, ensuring microservices are used only when appropriate and built correctly.