Follow SOLID design principles and maintain good information hiding:

Single Responsibility Principle (SRP): A class should have only one reason to change.
Open-Closed Principle (OCP): Open for extension, closed for modification.
Liskov Substitution Principle (LSP): Subclass objects should be substitutable for superclass objects.
Interface Segregation Principle (ISP): Many client-specific interfaces are better than one general-purpose interface.
Dependency Inversion Principle (DIP): High-level modules should not depend on low-level modules — both should depend on abstractions.

Individual code files should strive to stay under 200 lines. This is a goal, not a strict limit — justified outliers are fine.

Decompose extensive logic into multiple discrete files rather than accumulating lines in a single file. This promotes information hiding and keeps modules focused and comprehensible.

When writing code, consider:

Does it adhere to SOLID principles? If not, which principles are being violated?
Is the code organized into small, focused units?
Are there areas where information hiding could be improved?

solid-principles