Microservices Architecture

Overview

Microservices architecture structures a system as a set of small, independently deployable services. Each service owns a focused business capability, such as payments, catalog, or notifications.

Core Characteristics

• Single responsibility per service boundary
• Independent deployment pipelines
• Isolated data ownership per service
• API-based communication between services

flowchart LR
    C[Client] --> G[API Gateway]
    G --> U[User Service]
    G --> O[Order Service]
    G --> P[Payment Service]
    U --> UDB[(User DB)]
    O --> ODB[(Order DB)]
    P --> PDB[(Payment DB)]

Production Example

An e-commerce platform typically separates customer, checkout, and payment concerns.

services:
  user-service:
    image: company/user-service:2.4.1
  order-service:
    image: company/order-service:3.1.0
  payment-service:
    image: company/payment-service:1.8.3

When a payment bug appears, only the payment service requires rollback.

Operational Practices

• Use centralized logging with correlation IDs
• Apply circuit breakers for external dependencies
• Track service-level objectives (SLOs) per service
• Automate contract tests for API compatibility

Common Pitfalls

• Splitting services too early without clear domain boundaries
• Sharing a single database across many services
• Ignoring observability until incidents happen
• Treating synchronous calls as the default for every workflow

Key Takeaways

• Microservices improve independent delivery and scaling.
• Team ownership and observability are critical for stability.
• Strong boundaries and automation reduce architecture complexity.