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Refactoring legacy codebases: when and how

Refactoring legacy codebases: when and how

Creating software for your business is never a one-and-done process. Today’s technology systems grow and change over time, taking on new features and functionality alongside bug fixes and quality-of-life improvements.

Amid all this evolution and change, it’s essential to know when to radically reshape a piece of software and when it’s time to phase that solution out in favor of a replacement. In some cases, the system has reached a breaking point and must be phased out soon. In others, however, it’s better to refactor the code and hold onto this system that users have become accustomed to.

When components and libraries become outdated, software accumulates a number of temporary design decisions but it’s not yet time to retire the whole system, developers can perform a refactoring; changes that do not necessarily add new functionality but improve the overall design and quality of the code. In early stages, the cost of maintaining and updating the system has not yet become greater than the expense to replace it.

Sometimes refactoring a software product is just a stopgap to replacing the system in the foreseeable future, whereas in other cases it’s done with a longer view of the future. In either case, following some best practices on the engineering process side can help the vital software keep doing its work.

The two kinds of refactoring project

The right approach to refactoring depends on whether a given system is capable of further evolution. This is the difference between a short-term approach in anticipation of a transition and one that envisions continued use of the software in question.

Refactoring means adjusting the codebase to make sure it is maintained in keeping with best practices of software design. Rather than simply adding on new features or making quick fixes, engineers verify the integrity of their current codebase, make the technical decisions and work to improve the application code and infrastructure.

When a solution is nearing the end of its usable life, some light refactoring may help it cause fewer issues while the engineers are building its eventual replacement. If there is the potential to add more features over the coming years and the underlying code is worth retaining and actively maintaining, a more robust approach is used.

1. Going into maintenance mode

When a system has become old and will likely need replacement relatively soon, there is still value in refactoring its code to make it run smoothly. When engineers go into a refactoring project with this mindset, they’re acknowledging that the software likely won’t receive further new feature additions or user experience changes. The refactoring process is largely carried out in the name of tying up loose ends.

With the legacy system running well in maintenance mode, powered by its newly cleaned-up codebase, the engineers can work on developing and introducing the eventual successor software product. The two solutions can run in tandem for some time until the new option is considered strong and stable enough to cut over to that solution, at which point the old system is retired.

2. Prepping for the future

In other cases, a legacy system is still fundamentally usable and can function for years to come, with the addition of new features. In this case, the objective of refactoring is to make sure the software will be able to stand up to change and evolution.

This could mean gradual redesign and reengineering of the system as a whole, whatever it takes to ensure the solution keeps meeting users’ needs for the years ahead.

A system is a good candidate for this forward-looking method when it has received frequent maintenance and has incurred relatively little tech debt. Engineers should approach such a refactoring project with a roadmap, so they can make sure the system’s functionality is moving in the right direction. The refactoring will eventually touch every component of the software. This approach is more difficult than going to maintenance mode, but it could end up being less expensive than developing a whole new software product to replace the legacy system.

In either case, stepping in to perform refactoring is a valuable approach for businesses to take. In too many cases, companies run their systems until they become unbearably expensive, time-consuming and complex to maintain, dragging too many company resources into the upkeep process.

Taking a hands-off approach and essentially running systems until they break can weaken businesses’ ability to focus on new and strategic technology goals. This, in turn, can cause users to fall behind more forward-thinking competitors.

Admittedly, in some instances, there are cases when either type of refactoring won’t represent a suitable or sustainable approach going forward, and an even faster replacement cycle is called for. This happens when a system’s degraded condition has become so bad that it’s not just tough and expensive to maintain, but it’s actively causing problems by running in an unsuitable way.

Getting through refactoring: best practices for your engineers

Refactoring is best handled by engineers working with a strong set of fundamental engineering practices. This stands to reason because the end goal of refactoring is to create quality code that is easy to maintain, extend or upgrade.

The general philosophy that these engineers should keep in mind is that the software they are refactoring should help the company thrive and succeed. This means crafting systems that are free of user experience issues, critical bugs and overly complex workarounds.

Ideally, the software will fulfill its role, while also requiring less day-to-day upkeep from the engineers themselves, leaving them free to perform value-adding work, such as developing the next generation of systems or rolling out useful new features.

The following are a few of the priorities for engineers to keep in mind as they work on refactoring:

Implement code management best practices

The practices associated with continuous delivery are meant to create durable, low-risk code and are a great match for refactoring projects. Every engineer should be able to run the system locally, making at least daily or ideally ad-hoc builds — longer cycles between builds tend to let issues pile up, causing long backlogs of problems to work on. Delivering small, limited-scope changes on a rapid cadence, in accordance with continuous delivery best practices, will help the refactoring project progress. Engineers should obey industry standards for visibility and system health observation, tracking important metrics such as availability and system state. On a day-to-day basis, they can make quick, targeted changes based on that data.

Use continuous delivery

Changes in the nature of technology have caused overall shifts in the ways companies function. Today, an organization saddled with bad tech debt could be quickly overcome by a faster rival that’s able to iterate and evolve more quickly. Businesses across industries, even those that did not consider software development a major priority in decades past, now have to optimize their IT processes. The threat posed by the harmful kind of tech debt is ever-present, and when organizations see the signs that they’re suffering from this issue, they should act.

What form should that action take? It may involve a large-scale change, like ripping and replacing a major software tool that has become too unwieldy to use and update. This may bring short-term pain, but businesses can guard against having to go through the process multiple times by embracing continuous delivery and related best practices, ensuring that their new system is more future-proof.

Automate infrastructure

To establish an effective continuous delivery pipeline, engineers need to embrace automation. There should be an automated infrastructure setup that allows teams to build reproducible server environments. With this setup in place, it’s possible to craft a highly efficient quality assurance process and deal with any issues discovered in the code.

Automation is important at many steps, from constant testing to deployment of new builds into the cloud. The less manual work engineers are doing on these functions, the better. Following best practices saves time and effort, and reduces the chances of human error affecting the software being refactored.

Organize production operation

Once new releases are coming out, it’s important for engineers to ensure the standard procedures are all well documented. There should also be standardized approaches to everything from release process and troubleshooting to system recovery.

In some cases, pushing forward without an organized and standardized production process is what gets companies into trouble, incurring error-prone manual work, putting more pressure on production operation and technical support teams and contributing to customer dissatisfaction.

Working with Transcenda

Working with outside experts is one way to keep a refactoring project on track. These consultants can step in to make sure engineers are following best practices and proceeding in a way that will deliver long-term value for their organizations. The exact amount of engagement between outside experts and the internal team may depend on whether the refactoring job is a simpler project to put a solution into maintenance mode or a forward-looking operation to prepare a system for the years ahead. When Transcenda experts assist with a refactoring project, the engagement is customized to meet the organization’s needs, as no two software systems or business environments are exactly the same. The process starts with due diligence and system reviews to determine the current state of the technology and plan ideal next steps.

The following collaboration could be short or long, and is designed to create an outcome that will help the company’s software meet its business objectives, whatever kind of refactoring is needed.

To get started assessing your organization’s unique situation, reach out to Transcenda now.

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