All termsENGINEERING & ARCHITECTURE

System Architecture

DEFINITION

The high-level structure of a software system — its major components, their responsibilities, and how they communicate.

In depth

Good architecture answers three questions clearly: where does data live, how do components fail independently, and how does the system scale from 10 users to 10 million?

For SaaS, most early systems converge on a similar shape: a web/app tier, an API tier, a primary database, background workers, and a cache. The interesting architecture is everything that happens at the boundaries — auth, rate limits, integrations, retries.

Put it into practice

feature
Architecture generator
blog
MVP Architecture Patterns

Related terms

Monolith vs Microservices
Two opposing architectural patterns. Monolith: one deployable application. Microservices: many small services communicating over a network.

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Last reviewed 14 April 2026 by Abhi Verma.