Don't Let Old Code Be Your Unexploded Bomb: "Lighting the Fuse"

In Lucy Lewis's memoir, "Lighting the Fuse," she describes the legacy of unexploded bombs scattered across the UK from World War II. These bombs, left buried and dormant for decades, still pose a significant threat today. Similarly, in software development, old or legacy code left in the codebase can lie dormant, seemingly harmless, until the perfect storm of events triggers its execution, causing major disruptions. Here's why cleaning up your codebase is crucial and how you can do it:

Imagine a 1000 lb German bomb buried beneath a city street. Left undisturbed for years, it remains harmless. But when environmental changes or excavation work disturb it, chaos ensues—evacuations, safety zones, and urgent efforts to disarm it safely.

The Parallels in Code:

Software development faces a similar challenge with legacy code. Often, old code is left in the system, replaced by new solutions and believed to be inert. However, under certain conditions—perhaps a unique user interaction, an unexpected data input, or changes in dependencies—the old code can suddenly trigger, causing severe issues.

So why clean up?

• Risk Mitigation: Old code is a potential risk. It may not align with current standards, security practices, or system architecture.
• Maintainability: Cluttered codebases are harder to maintain and debug. Cleaning up improves readability and reduces technical debt.
• Performance: Unused code can degrade performance, affecting the overall system efficiency.

So where do you start - Code Bomb disposal approach:

• Identify Old Code: Conduct regular code reviews to identify sections of code that are no longer used or are redundant.
• Evaluate Impact: Before removal, evaluate the impact of the old code on the system. Ensure no unexpected dependencies exist.
• Refactor or Remove: Refactor the code to align with current standards or safely remove it. Document reasons for removal.
• Testing and Validation: Test the system thoroughly after code removal to ensure no unintended consequences.
• Continuous Maintenance: Regularly update and maintain the codebase to prevent the accumulation of legacy code.

Just as bomb disposal experts secure and disarm unexploded bombs, software developers must clean up their codebases to prevent future disruptions. Take the extra time to make your codebase safe for your future self and your teammates. Your efforts will pay off in improved system stability, reduced downtime, and easier maintenance.

How do you do this on your teams ?

References:

https://www.amazon.co.uk/Lighting-Fuse-Lucy-Lewis/dp/184188393X

https://en.wikipedia.org/wiki/Unexploded_ordnance