Coding Horrors: Tales of Complex Codebases

By Roni Dover |

The terrifying tales of complex codebase nightmares that hit too close to home.

If you’ve been in the software development world for a while, you’ve probably come across a complex codebase that makes you want to scream, cry, or just curl up in a corner.

These complex codebases can range from a tangled mess of spaghetti code to a bloated monolith with complex dependencies and insufficient test coverage. In this article, we’ll dive into the horrors of difficult-to-maintain codebases, drawing from the experiences of developers who have shared their stories on Reddit.

Grab a cup of coffee, and brace yourself for some truly terrifying tales.

A Classy Tower Of Hanoi

Ever heard the saying, “There’s no problem that can’t be solved by adding another layer of abstraction”? It’s tempting to think that organizing code into neat layers will make everything clear and tidy. It sounds great in theory, but in reality, things can get out of hand pretty quickly. Abstractions start to leak and pile up, hiding the important bits of code you really need to see. Before you know it, what was meant to be a simple debugging task turns into a wild goose chase through a maze of classes and objects.

Reddit user zoozla shared a story about working on a massive Java monolith that was part of the foreign exchange system used by banks to trade currency. The complex codebase featured a dizzying 8 layers of abstract classes with just one concrete class at the bottom. It also contained an almost Turing-complete language in XML for parsing legacy binary files. To make matters worse, running the unit tests modified the dev database, requiring manual reseeding after each run. Zoozla spent months attempting to refactor the worst parts of the code, but with little success.

Very Generic Code

Sometimes even the best of intentions can lead to unintended consequences. That’s what often happens when developers try to create the perfect, flexible software. They dive headfirst into a world of intricate abstractions and dependencies, thinking they’re making something truly adaptable. But before they know it, they’re stuck in a tangled mess of code that makes even the tiniest changes a huge pain.

Shnorkylutyun experienced the nightmares of nested generics and wrappers around every possible base type in a Java app. There were mappings between the wrappers and different types of wrappers, along with generic classes describing generic forms with 10+ fields, each with separate generics for every field’s type. Form wizards with up to 6 generic types per page only added to the chaos. Rearranging the order of two fields in a form was a cause for celebration if both were Strings.

Dreams Of Smalltalk

You know that saying, “When all you have is a hammer, everything looks like a nail”? Well, imagine a team of developers back in the late ’90s who were so in love with Smalltalk that they tried to shoehorn its concepts into a C application. They ended up with a mind-boggling complex codebase that relied on sending text strings for processing rather than using good old function calls. Add in massive source files and a baffling misuse of PostgreSQL, and you’ve got yourself a recipe for one epic headache.

json-123 shared a tale about a 5-million-line C application originally written for Solaris in the late ’90s. The original developers attempted to recreate Smalltalk in C by sending text strings to be processed rather than calling functions. This complex codebase had massive source files with over 150k lines of code, breaking many IDEs. To make matters worse, the app used PostgreSQL as a fancy file-locking mechanism for flat files instead of migrating the data to tables.

Oddly Complete test coverage  

Sometimes, when developers are faced with tight deadlines, mounting frustration, and a dash of resentment towards misguided management, things can take a strange turn in the codebase. Instead of carefully crafted solutions, the pressure to deliver can lead to unusual and downright bizarre results.

As a prime example, aceluby tells of a Java app with 99% code coverage in tests (!) but without a single assertion! The tests only checked if exceptions were thrown, providing very little confidence in the code’s correctness. It’s not fun to maintain such a complex codebase, but imagine being frustrated and stressed enough to do this in the first place!

No seniors in sight

You know that feeling when you walk into a room and can’t find what you’re looking for because there’s just so much shit everywhere? That’s how it feels to dive into a codebase that’s been growing unchecked for years. Without anyone steering the ship, it becomes a chaotic maze of twisty little passages, all alike.

zasch described a project with about 570 modules in total, including “test modules” that only tested other modules. The monolithic codebase had grown over 20 years without an architect in sight, and everyone working on the project struggled to make sense of it. Debugging was a nightmare, and importing the entire codebase into an IDE caused it to freeze. The only recent achievement was updating to Maven 3 and Java 8.

Real Men Don’t Need Source Control

And then there are situations where try as you might you just can’t justify what the previous developers did. Some people just need to have their coding license revoked. Permanently.

fuseboy shared a story about a complex touchscreen kiosk app built in Java Swing with the purest spaghetti code imaginable. The codebase had no encapsulation, layering, or interfaces, and variables were public to make data sharing easier between classes. Even more astonishing, there was no build process. Developers privately built their classes at the command line and emailed them to the tech lead.

The Future Isn’t Pretty with complex codebases

These horrible complex codebases are unfortunately more common than we’d like to admit. And when developers are tasked with fixing them, it’s like being handed a map to a maze without an end.

Sure, there are tools and methodologies out there that are supposed to help, like static code analyzers and refactoring tools, but they often fall short in the face of such complexity and scale.

What’s worse is when management fails to grasp the gravity of the situation or simply prioritizes short-term goals over long-term maintainability. It can be discouraging for developers, who are already struggling to tackle these behemoths.

And the older these enterprise-grade piles of duct tape get, the bigger they become. More developers are needed to work on them, and rewrites tend to cause more problems than they solve.

Now It’s Your Turn

Most developers have a tale like this. What’s yours?

What kind of code monsters have you fought?

Did you win? Tell us here.