Understanding Business System Complexity in Software Development

This article explores the fundamental challenges of software development efficiency and business system complexity. The author begins by questioning why team expansion often occurs not due to business growth, but due to increasing workload—a phenomenon many development teams can relate to.

The core problem lies in the relationship between functionality and development cost. While ideally this should follow a linear or logarithmic curve (meaning each new feature becomes progressively easier to implement), the reality is an exponential curve—adding more features makes development increasingly difficult rather than easier.

The article introduces Fred P. Brooks' concept from "No Silver Bullet": software complexity can be divided into Essential Complexity (inherent complexity of the functionality itself) and Accidental Complexity (additional complexity introduced by engineering constraints and human communication issues). Engineering efficiency tools primarily address accidental complexity, but if essential complexity accounts for 80% of the work, tool optimization alone is insufficient.

Two fundamental causes of business system complexity are identified:

1. Hidden Coupling Between Features : As systems evolve, features become inadvertently interconnected. The article provides a detailed example of a "business card system" in a community app—initially simple, it eventually coupled with multiple subsystems (achievement system, membership system, verification system) and various display scenarios (feeds, comments, profile pages). Each new feature requirement then requires modifications across multiple previously unrelated modules.

2. Inevitable Code Decay : The author argues that code decay is unavoidable because architecture design can only address current requirements and is inherently short-sighted. Using "Chinese-style agile development" as an example, developers typically work with limited information about the overall system, making comprehensive architecture design impossible. Even experienced architects cannot foresee future requirements, leading to structural limitations that accumulate over time.

The article concludes that addressing code decay requires both code anti-corrosion measures and knowledge documentation—though these are often neglected due to the immediate pressure to deliver features. Structural decay can only be addressed through refactoring, which essentially represents learning from past mistakes with hindsight.