Do You Understand the Debt You Have to Pay?

I was fortunate to start my career with people who truly cared about code quality. Early on, I learned why this matters and how continuous attention to quality positively impacts customer satisfaction. This experience made it natural for me to improve legacy code and constantly seek further enhancements.

However, at the beginning of my journey, my perspective was narrow—I saw only the code. So, my efforts focused solely on refactoring. Fast forward to today, I've learned that there are many more ways to improve software. There are also several strategies you can explore to choose the right approach for your situation.

Improvements = Change

It’s important to remember that any refactoring, redesign, or re-architecture introduces a risk of breaking something that currently works. While in theory these changes shouldn't break functionality, in practice, the risk varies across applications and depends heavily on the development practices surrounding them. But make no mistake: the risk is real.

If you decide to address technical debt, accept that risk and communicate it clearly with everyone involved. There are ways to mitigate and manage it effectively, but something may still go wrong. Transparency helps ensure that one failure doesn't undermine the overall improvement effort.

What Strategies Do You Have?

Leave It As It Is

Our inner perfectionist may protest, but sometimes the best approach to dealing with legacy systems is to leave them untouched. No refactoring, no redesign—just minimal maintenance as needed. Focus your energy elsewhere, particularly when under pressure from other priorities.

Continuous Refactoring

Not every project needs a full modernization or complete re-architecture. In some cases, ongoing refactoring can make a huge difference. Within months, you may observe improvements in both code quality and delivery speed.

Introducing Code Architecture

Sometimes, refactoring alone isn't enough. Certain applications need a deliberate plan toward an agreed-upon architecture. This architecture must be well-communicated, understood, and supported by the entire team. Everyone should know how to move toward it.

Divide and Conquer

Some systems are large enough to support multiple subdomains. In such cases, visualizing and implementing boundaries between them helps maintain consistent language, encapsulate implementation details, and reduce cognitive load during development.

How to Make the Right Decision?

Here are some questions that can help you make a more informed decision. Remember, context matters. The more you learn and data you gather, the better your decision will be.

Should I Leave It As It Is?

If the application is running smoothly and nobody is actively working on it, you might be able to leave it alone. Still, assess potential upgrades to the language, framework, libraries, or infrastructure. Sometimes it makes sense to invest in reducing technical debt to make future upgrades less risky.

Understand how the application aligns with your company's strategy. If it’s scheduled for decommissioning, your efforts might be better spent elsewhere. However, even in this scenario, check what the decommissioning process entails. If migrating data or users is required, some improvements may still be worthwhile to minimize risk and pain later.

Can Continuous Refactoring Pay the Debt?

Refactoring is a great way to continuously counteract code degradation. But when is it a suitable strategy for legacy code?

If the application is less than a year old, continuous refactoring can lead to impressive improvements in a short time. The codebase is likely still small enough to be manageable, and upcoming features can be implemented with better design in mind.

For older applications (2–3 years or more), ask yourself: how many teams are involved? If a single team is maintaining it and delivery pace remains steady, continuous refactoring may still work. But at this stage, it may be time to consider other strategies as well.

Will a New Code Architecture Be Enough?

If the application is over a year old and maintained by one or two teams, introducing a shared architectural vision can help. A well-defined architecture gives engineers clarity on the domain and guides how to add new features.

With only one or two teams, it’s easier to make collective decisions. The risk of misalignment is low, and such discussions shouldn't block delivery. But if more than two teams are involved, another strategy may be more appropriate.

Divide and Conquer

Now we’re talking about complex systems with multiple teams actively working on them. In this case, clearly define boundaries within the platform and assign code ownership to each team. These boundaries may be architectural, infrastructural, or both.

Goals include:

• Eliminating shared code and infrastructure where possible
• Enabling team autonomy to improve their respective code areas

Reducing inter-team dependencies accelerates delivery. While cross-team collaboration is valuable, autonomy helps teams make long-term improvements with confidence, knowing their decisions won't be undone by others.

Summary

There are many nuances to the above strategies, but even this level of detail provides a good starting point. I encourage you to challenge these ideas and ask questions in the comments—I’d be happy to explore this topic further.

And remember:

• Not every legacy system needs to be refactored
• A new architecture may not always help
• A rewrite isn’t always the best choice
• Sometimes, leaving things as they are can be a smart move