Cracking Legacy Code (ENG)

Developer Stories: Tales from our CC.Talent’s seasoned developers

‘Code is very easy to write. But we spent the majority of our time reading them.’ 

Imagine diving into a sea of code, each line a breadcrumb left behind by countless developers before you. It's a daunting task, decoding their intentions, unraveling their logic, and occasionally shaking your head in disbelief at what you find. For countless software engineers, there's an undeniable allure to greenfield projects – they offer a fresh start, a clean slate untouched by the complexities of past decisions. But as you climb the ladder to senior positions, a shift occurs. It becomes clear that dismissing the challenges of legacy code as wishful thinking overlooks the invaluable lessons and personal growth that come from wrestling with the intricacies of past choices.

At CC.Talent, our senior developers have weathered their fair share of battles with legacy code. From the frustrating to the fascinating, they've seen it all. In this blog, we're pulling back the curtain to share their stories, insights, and hard-earned wisdom. So pour yourself a cup of coffee, and join us as we journey through the highs and lows of legacy code – because sometimes, the most tangled paths lead to the most rewarding discoveries.

Hating legacy code is fair! Right? 

Legacy code, essentially older codebases, often carries negative connotations such as slowness, insecurity, or complexity. These perceptions, stemming from factors like technical debt or maintenance challenges, can put off developers from engaging with them. However, there are legacy systems that age well! Due to engineers prioritizing maintainability. Through practices like complete documentation, integration guides, and upgrade procedures, these systems remain relevant and effective despite their age.

When to worry about legacy code? Well.. when it actually matters!

Let's take a look at this from the perspective of one of our developers: 

There was this time when I took the reins on revamping a particular module. It was a real mess, courtesy of the previous developer's handiwork, and I felt it was my duty to tidy it up for the team (and any future developers) to work with ease and build on top of this module. I poured my heart and soul into it for a week and a half, getting it through code review, and finally rolling it out into production. It was a thing of beauty, a masterpiece crafted by my own hands.

But, after a series of eye-opening meetings, it dawned on us that this module hardly saw the light of day. Clients barely touched it—maybe 3 or 4 times a year, if we were lucky. That was a week and a half of my life, gone. Poof! Was it worth it, you might ask? Sure, cleaning up code is noble, but only when it truly matters.

Trust and consult your data!

Data, data, data…. 

What's the takeaway here? Trust and consult your data. Let it guide your decisions. Don't hesitate to question your assumptions; gather more data to back them up. Reach out to your customers, and your stakeholders. Have conversations. That's the magic of dealing with legacy systems – there's usually a goldmine of data to tap into for making informed choices.

In the end, do you know what differentiates a messy legacy codebase from a clean greenfield project? Customers, users, and revenue – and that’s where the beauty truly lies.

Let's dive into some common challenges 

When it comes to tackling legacy systems, we'll be focusing on three main challenges: Maintenance, Addressing Technical Debt, and Upgrading Dependencies.

• Maintaining Legacy Systems

Understanding the purpose behind a system is key when diving into its legacy code. One trick? Reach out to the previous engineers and maintainers – a quick call can offer valuable insights. Dive into their past issues and pull requests, especially the ones with the most comments or recent activity. Pay attention to their coding style and conventions. Another helpful tip? Explore their test suites, particularly the integration and unit tests.

By gaining a deeper understanding of their approach, you'll find it easier to adapt to their coding standards, which is crucial when introducing new code. This, in turn, enhances the overall maintainability of the project.

• Dealing with Technical Debt

Technical debt often crops up when we're racing against the clock to meet tight deadlines during development. To tackle it effectively, swift identification and flagging of issues are key. Whether it's adding a handy TODO/FIXME/TECH-DEBT comment or opening a new issue/ticket, prompt action is crucial. It's also wise to ensure some form of black box testing is in place before making any changes, as this helps catch potential problems and ensures the original behavior of the application remains intact.

Once you've pinpointed the areas of technical debt, it's time to devise a plan. Create a timeline based on a prioritized list of tasks, breaking down the work into manageable chunks. Consider balancing this effort with ongoing feature development and bug fixes.

Regular reviews with your peers are essential to catch any potential new issues.

Lastly, documenting the changes you make to address technical debt is essential. This includes explaining the reasoning behind each decision and sharing any lessons learned along the way. While it may seem like a tedious task, it serves as a valuable resource for future developers and helps prevent similar debt from resurfacing.

• Upgrading Dependencies

One big reason why teams decide to migrate legacy code is to keep things safe and up-to-date. Whether it's fixing security issues, supporting new third-party applications, or accessing features in newer package versions. This is especially true for popular languages like PHP, Javascript/Typescript, and .Net. Since so many people use and support these languages, there's always someone adding or fixing things – which could sometimes cause hiccups in your current setup.

When it comes to updating dependencies, it's important to take a methodical approach. Keep track of all the changes you make internally, document each step of the process, and have a fail-safe plan. This way, if something goes wrong, you can easily go back to a previous version. It might take a bit more time, but it's worth it in the long run – especially when you're dealing with multiple versions of dependencies.

Concluding

Navigating through legacy code isn't always easy. From finding the intentions of previous developers to tackling technical debt and upgrading dependencies, each step presents its own unique challenges. But with the right of data, transparent communication with stakeholders, and a step-by-step approach, we are ready to tackle these challenges. 

From the lessons our CC.Talent developers have shared, one lesson stands out: knowing where to concentrate our efforts. The temptation to tidy up code is always there, but we've learned that true impact lies in understanding how our actions directly influence customers, users, and revenue. By matching our actions with results, we not only maintain the functionality and importance of old systems but also boost business success!

Stay tuned for our follow-up article! 

The journey through legacy code continues in our upcoming article. We'll delve into a real-life case study presented by one of our Senior Developers.

Discover the ins and outs of modernizing outdated applications and shifting infrastructure to managed cloud services. Be sure to follow us on LinkedIn so you stay in the loop!

About CC.Talent developer stories & CC.Talent

CC.Talent’s Developer Stories is a project driven by our own developers. This community initiative was launched as a platform for us to share knowledge, discuss daily experiences, and connect with peers who share similar roles but work for different clients. The subjects and knowledge we share are valuable and deserve a wider audience, that is how ‘Developer Stories’ come to life. 

Credits to our knowledge hub

A big shoutout to our Knowledge Hub contributors: Fred, Andrew, Lance & John for taking ownership of this first piece of content. We are looking forward to more knowledge-sharing, more fun, and more impactful contributions!

Andrew

Tech Lead / Senior Software Engineer

Fred

Lead Developer

Lance

Senior Developer

John

Senior Software Engineer