Almost every developer must've worked on at least one legacy project in their career.
And the first reaction is almost always the same.
You open the codebase and think,
"Who wrote this code?"
"Why is this such a mess?"
"I can do a lot better than this"
... something like this.
I too thought the same. And this reaction is justified. Because the first look is rarely pleasant. Confusing structure, outdated patterns, and code that feels impossible to reason about.
When I was first assigned to a legacy project, I wasn't excited at all.
It wasn't new, it wasn't shiny, and it definitely wasn't something I could show off. The codebase was large, the logic was spread across files, and even a small change felt risky. I kept wondering how anyone managed to build and maintain something like this.
It was a scary experience. For every small change, I've spent most of the time navigating the code than actually writing it. A lot of syntax actually felt unfamiliar to me. There was no package managers, no third party libraries, no proper documentation. Everything was written from scratch.
For a modern programmer like me, who uses third party libraries and packages for everything like it is normal, it definitely was a scary experience.
At first, everything felt difficult. Progress was slow and mistakes felt expensive. At some point, I even wondered, why aren't we migrating it to some new and shiny tech.
But as I spent more time navigating the codebase, reading, tracing, and understanding the processes, it started getting easier. I no longer felt lost every time I opened a file. I know where to look, which parts were fragile, and which ones could be changed safely. Debugging became faster, changes became more deliberate, and the fear of breaking things slowly faded away.
Working on legacy projects taught me many things. I no longer solely rely on third party libraries. I was realized package managers and libraries are good to have, but not necessarily needed. I got to know how systems actually work on ground level.
As I continued working on, I've started to admire the developers that built those systems decades ago, from scratch without any of the modern resources available to them. At first, I thought that the legacy developers only wrote messy code, but as time passes, I've started to appreciate the fact that they did their very best with the limited resources available to them amid tight deadlines and the effort they put into building everything from scratch.
Working on legacy projects made me a better programmer than I can imagine. It gave me the confidence to take up new challenges and work on new things. I am no longer afraid of working on things I don't know, because I am confident that I can learn.
Whenever I am assigned to legacy projects, I've started to look at them not as obstacles, but opportunities. Opportunities to learn more about complex systems and get used to the code of programming languages.
I no longer advise on migrating legacy projects into new stack. In fact, I advise against it. Because I believe that legacy projects are more stable than most of the project that are developed with modern tech stack.
For everyone who are working on legacy projects, I want to share some things from my experience.
1. Legacy projects are not obstacles for your career, but great opportunities for you to learn and grow.
2. Legacy projects are not outdated. They are just simple, boring and stable.
3. Legacy projects often lack good documentation, so when you are navigating through code, make sure to take notes properly. So that it may help you in the future or others who work on it.
4. When you came across tasks that couldn't be done using legacy stack, try to bridge that gap using modern stack. But don't actually try to migrate entire working system into modern stack, just because it's outdated.
Conclusion :
Legacy codebases changed the way I look at software engineering.
They taught me that good software isn't always clean or modern, but it's software that continues to deliver value overtime. More importantly, working on legacy stacks helped me become a better programmer and a better architect.
Understanding, maintaining, and improving systems that already exist is deeply rewarding. That's why, today, I genuinely enjoy working with legacy code.