Programming Principles

While navigating the seas of Java Design Patterns and exploring the treasures of Principles Wiki, I felt the need for a compass—a checklist to guide us through the vast ocean of design principles during the various phases of feature development and release.

In the ever-changing tides of software development, there’s no mythical map or silver bullet that solves every challenge. The waters are tricky—some principles may clash like opposing currents, making it impossible to chart a course that satisfies them all. But having a well-structured checklist for each phase—discussion, design, development, and testing—can act as our guiding star, helping us navigate toward better designs.

Though we may not always reach the perfect destination, striving to stay aligned with these principles ensures our voyage is deliberate and our solutions are more resilient, maintainable, and enduring.

1. Discussion Phase

Goal: Define the problem, requirements, and approach while ensuring alignment with design principles.

• Requirement Clarity:
  • Is the problem clearly defined and validated?
  • Are all assumptions documented?
• Focus on the Problem:
  • Is the solution addressing the core issue without scope creep?
  • Are unnecessary features avoided (YAGNI)?
• High-Level Trade-Off Analysis:
  • Have the pros and cons of various approaches been discussed?
  • Are trade-offs documented and justified?
• Scalability and Performance Considerations:
  • Are future growth and performance needs considered?
  • Are bottlenecks or risks identified?
• Collaboration:
  • Are stakeholders aligned on the problem and proposed solution?
  • Have relevant feedback loops been established?

2. Designing Phase

Goal: Translate the requirements into a robust, scalable, and maintainable design.

• Design Principles:
  • Is the design simple (KISS) and easy to understand?
  • Does it adhere to SOLID principles and separation of concerns?
  • Does it minimise dependencies and follow the Law of Demeter?
• Flexibility and Adaptability:
  • Can the design handle future changes with minimal disruption (Open/Closed Principle)?
  • Are internal details encapsulated properly?
• Modularity and Reusability:
  • Are components decoupled and reusable (DRY Principle)?
  • Is duplication avoided?
• Error Handling and Resilience:
  • Does the design ensure robust error handling?
  • Are fallback and rollback mechanisms in place?
• Documentation:
  • Are design decisions, constraints, and trade-offs documented?
  • Is there a clear, high-level overview of the architecture?

3. Development Phase

Goal: Implement the design with clean, efficient, and maintainable code.

• Code Clarity:
  • Is the code easy to read with meaningful names and proper formatting?
  • Does it follow established coding standards?
• Implementation of Principles:
  • Does each module/class adhere to the Single Responsibility Principle (SRP)?
  • Is functionality implemented in a way that respects the Principle of Least Astonishment?
• Avoid Hard-Coding:
  • Are values and configurations externalised appropriately?
• Error Handling:
  • Are inputs validated and edge cases handled?
  • Is the code idempotent where necessary?
• Performance and Scalability:
  • Are resources (CPU, memory, I/O) used efficiently?
  • Are any known performance issues flagged for optimisation later?
• Self-Documenting Code:
  • Does the code minimise reliance on external documentation by being self-explanatory?

4. Testing Phase

Goal: Validate that the implementation meets requirements and behaves as expected under all conditions.

• Test Coverage:
  • Are unit, integration, and end-to-end tests implemented?
  • Are edge cases and error scenarios tested?
• Automated Testing:
  • Are tests automated where possible for continuous integration?
• Regression Testing:
  • Are mechanisms in place to ensure that new changes do not break existing functionality?
• Performance Testing:
  • Are performance metrics monitored to identify bottlenecks?
  • Is the system tested under load to ensure scalability?
• Validation of Resilience:
  • Are fallback and rollback mechanisms tested?
  • Are error-handling pathways validated?
• Iterative Improvements:
  • Are feedback loops utilised to refine the implementation?

As we sail through the complexities of software design, this checklist is meant to be a tool in your navigation toolkit. While we may not always chart the perfect course, adhering to these principles throughout the various phases of development helps steer us closer to robust, maintainable solutions. The journey may be long, and the seas may be unpredictable, but each step taken with purpose and thoughtfulness brings us closer to mastering the craft of software engineering.