Legacy code: What is it and the best way to upgrade it

Dealing with older code and code you didn’t write can be an obstacle for you on software development. However, unless you’re starting a project from scratch, it’s inevitable. So, you would want to have a better way of working with it, and “Legacy code” is one of the best options for you. Whether you have an exact definition of it or not, you’ve probably heard the term tossed around a bit. In fact, you may have tossed it around yourself.

Legacy code definition and upgrade
Legacy code

All things considered, if you’ve been in the game for some time, you might have realized that everyone has a different opinion on what good code looks like, and Legacy code is of no exception. So now, we – ArrowHiTech would like to introduce to you guys the finest definition of this term of coding. We also want to show some of the best ways on how to upgrade it for your store’s set of code.

But first, let’s go to the definitions.

What is Legacy code?

This term of coding is merely the source code inherited from someone else or inherited from an older version of the software. It can also refer to unsupported operating systems, hardware, and formats. On some occasions, it can also be any code that you don’t understand and that’s difficult to change. Legacy code is mostly converted to a modern software language and platform, yet it sometimes carried into new environments for retaining familiar user functionality.

Why is it a challenge for your store?

The biggest challenge with working with legacy code maybe your assumptions about it. You may think the code is bad, or you may not understand the idea of the predecessor. But the truth is, there’s usually is a reason why the code is how it is. And, if you didn’t write it, you might not know that reason. That’s why care needs to be taken when making improvements to the codebase. And that’s why it’s important to know when to maintain or to change it.

Some of the best ways to upgrade Legacy code

Once you’re confident that the product you’re working on needs an upgrade, it’s time to make an informed decision about the direction of the change. Let’s go through some of the best ways to upgrade it.

#1. Rewrite on a large scale

The first and one of the first-thought options that every developer thinks about is changing the codebase from scratch. But total rewrites are extremely time-consuming and bound to incur considerable cost. You may also end up with an app that’s unfit for release for months or even years. Plus, the larger an application is, the harder it may be for developers to provide maintenance and add new features in-progress. TL;DR: It’s costly and hard.

#2. Add the new ones onto the remaining Legacy code

The next option that some of you may have thought about is to add new features built with new technology to the existing codebase. Ideally, you shouldn’t touch the old technology and should instead keep the new features separate. Unfortunately, such an outcome is relatively rare: New features almost always need to be integrated with old ones. This also requires a detailed plan, as the matter is complicated to get right.

Add the news to the olds

Yet, the consequences may be of your consideration. This is because of the long-term fragility of the original codebase, especially with regard to potential security vulnerabilities or bugs, this architecture isn’t built to last. In practice, leaving outdated code as-is means you’re waiting for it to eventually fail for good. TL;DR: Need the ultimate and detailed plan for success.

#3. Upgrade Legacy code by Hybrid building

These two above are so not the best thing for you to choose for your software development. This is when the hybrid one comes in handy. This option, like the Big Bang rewrite, requires changing out the whole of your old code. But unlike the first option, the rewrite should be spread out over a period of time – say a couple of years – to minimize technical debt and financial cost. This incremental approach will be based on your vision, which is crucial here.

Hybrid building in legacy code
Hybrid building

After all, you may have to know what to change first: Some features are core and business-critical, while others take more of a supporting role. Working on multiple layers will be easier with a clear goal in mind. Yet, you have to be careful. This is because when you add new features in the form of separate microservices, they’ll eat the business logic of your legacy code piece by piece.

Final words of Legacy code

That should be it! Here is the definition of legacy code, as well as some of the best ways to upgrade it. All in all, the world’s software runs on code that has been passed on from team to team. Dealing with legacy code is an everyday reality. So, you need to make sure your set of code is great in the long-term settlement, so you can continue your journey of software development to the next level.

We – ArrowHiTech is proud to be one of the most well-established outsourcing companies all around the world. With over 14 years of experience, we can provide the best software development services for your business.

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If you have any questions, don’t hesitate to contact us!