Does your codebase have Mr. Burns Syndrome?

One of my favorite engineering lessons comes from a Simpsons episode where Mr. Burns learns he has every disease imaginable. His health persists only because the germs are in a stalemate, deluding Burns into thinking he's invincible.

DOCTOR: Well- Here is the door to your body. You see? And these are oversized novelty germs... Here's what happens when they all try to get through the door at once…

MR. BURNS: So what you're saying is I'm indestructible.

DOCTOR: Oh, no, no. In fact, even a slight breeze could–

MR. BURNS: Indestructible.

Unfortunately, "Mr. Burns Syndrome" is something that's all too common to see when you're working with code that's passed through many hands.

Diagnosis

The diabolical nature of Mr. Burns Syndrome is that the code ostensibly works. It's probably "working" in production right now. But any slight scratch to the surface quickly reveals issues: Even the most trivial change cascades into a mystifying avalanche of bugs.

Symptoms of Mr. Burns Syndrome include:

• One bug masking another bug that's masking yet another bug.
• Inaccessible code paths and swallowed errors.
• Race conditions a-go-go.

What's worse, there are likely many generations of patches that are compounding the problem.

Complications

Aside from the code itself, there are three major challenges you'll often run into when you're dealing with Mr. Burns Syndrome:

• The business requirements around the code may be murky.
• The code either doesn't have tests or has tests that really only serve to goose up code coverage numbers.
• Your stakeholders may be unsympathetic: The code's been "working" just fine, after all, so why is this a problem now?

Your own team could also prove a challenge: Junior engineers thrash at Mr. Burns Syndrome-afflicted code without raising flags, piling more convolutions into the codebase. Mid- and senior-level engineers may refuse to work on the code at all, declaring that a full rewrite is the only viable path forward.

Treatment & Recovery

1. Clarify your requirements. What are the inputs and outputs supposed to be? What's the logical flow that the code should be following? Map it out and write it down.
2. Test your main logical flow. Code with Mr. Burns Syndrome is often pretty dense and hard to unpack. Start by focusing on automated tests for higher-level code (or even on integration tests.) Identify where the gaps and breaks are against your business rules before you worry too much about testing more granular sections of code.
3. Evaluate your options. It's time to make a judgment call: How far off is the code from satisfying the business requirements? Are business-critical issues most effectively resolved by cleaning up individual functions? Rewriting only the most problematic functions? Doing a full rewrite?
4. Make a plan of attack. You now have the ammo you need to have a meaningful conversation with your stakeholders and your team. Take them through the problem and the options. Help them weigh the impacts to decide on the right course of action as a team.

It's always the most tempting to say the code needs a full rewrite because... well, the code is ugly and your team hates it. But remember: Everything you do on a project is coming at the expense of everything else that you could do.

Conclusion

Addressing Mr. Burns Syndrome isn't just about fixing bugs; it's about taking a methodical approach to understanding and resolving the underlying issues.

By getting clear on requirements, enhancing test coverage, and making strategic decisions about refactoring or rewriting, we can turn a messy codebase into something manageable.

In the end, it's all about communicating effectively with stakeholders and showing them the risks and benefits. With the right approach, we can tackle even the most daunting technical debt and keep our projects on track.