Microservices and Distributed Systems

Microservices architecture splits a system into independently deployable services, each owning a business capability. It trades the simplicity of a monolith for flexibility in scaling, deployment, and technology choice. That trade only pays off when the organizational and technical complexity is justified.

When to use microservices vs monolith

The decision depends on team size, domain complexity, and operational maturity.

Factor	Monolith favored	Microservices favored
Team size	Small team (fewer than 10 developers)	Multiple autonomous teams that need independent release cycles
Domain complexity	Simple or poorly understood domain	Well-understood domain with clear bounded contexts
Deployment cadence	Infrequent releases are acceptable	Different parts of the system need to ship at different speeds
Scaling needs	Uniform load across the application	Specific components need independent scaling
Operational maturity	Limited infrastructure automation	Mature CI/CD, monitoring, and container orchestration
Data isolation	Shared database is manageable	Services need independent data stores and schemas

Start monolithic unless you have a clear reason not to. A well-structured modular monolith can be decomposed later. A premature microservices architecture adds distributed systems complexity without matching benefit.