Software Architecture Design: Basic Concepts, Sources of Complexity, Three Principles, and Design Process

The purpose of architecture design is to address system complexity, not to achieve every possible quality attribute; instead, designers should identify real business challenges and solve them in a targeted manner, balancing effort and benefit.

Complexity in architecture stems from several dimensions:

High Performance

High Availability

Scalability

Low Cost, Security, Scale

The three guiding principles of architecture design are:

Appropriateness Principle

Good architectures are created within the constraints of current resources, personnel, and business needs, delivering maximum effect without over‑engineering; copying large‑company solutions without context often leads to failure.

Simplicity Principle

When both simple and complex solutions satisfy requirements, the simpler one should be chosen, following the KISS (Keep It Simple, Stupid!) philosophy.

Evolution Principle

Software systems must evolve with business changes; attempting to design a static, all‑encompassing architecture is unrealistic. Architects should avoid the trap of “one‑shot” designs and instead embrace incremental evolution.

Practical advice includes:

Design an architecture that meets current business needs.

Iteratively refine the architecture, preserving good designs and discarding flawed ones.

When business changes, extend, refactor, or even rewrite the architecture while retaining valuable lessons and logic.

The typical architecture design process is illustrated in the following diagram:

Source: juejin.im/post/5b2c6669e51d4558c91ba776