What Makes Code Good or Bad? Practical Standards for Maintainable Software

The article explores the question "what is good code and what is bad code," clarifying that bad code is essentially code that either fails to work correctly or is difficult to modify.

Good code is defined as code that accomplishes its intended purpose and can be changed with minimal effort; all other quality criteria stem from these two fundamentals.

This perspective rejects the pursuit of "code art" or over‑design, emphasizing practical standards because code quality directly impacts development efficiency and product quality.

Data shows that teams with high‑quality code spend 44% of their time developing new features instead of fixing bugs or patching problems, representing a significant efficiency gain.

Typical characteristics of bad code include:

Hard to maintain

Poor scalability

Low readability

Difficult to test

Insecure

Poor performance

Non‑compliant with standards

Ultimately, the two decisive factors are whether the code can be used and whether it is easy to change.

Readability should serve any business‑aware stakeholder, not just the original author; for example, doctors should grasp core logic in medical software, and players should understand the intent behind game code.

Key recommendations for writing good code:

Keep code small and focused, each part doing one thing

Use clear, business‑aligned naming

Minimize side effects and keep state controllable

Adopt Test‑Driven Development (TDD) to ensure maintainability

Prioritize readability and changeability over mere elegance or flashy techniques

In conclusion, writing good code is not about showing off; it is about enabling the team and one’s future self to handle changes smoothly and efficiently.