"It Works on My Machine" Is Now "It Works in the Prompt."
In early 2025, the tech world went crazy for "Vibe Coding." The promise was seductive: You don't need to know how to code! Just vibe with the AI! Just tell Claude to 'make it pop'!
Managers fired their Senior Engineers. They hired "AI Natives." They shipped features at light speed.
Now, it is December 2025. And the bill has come due.
I am seeing codebases that look like a crime scene.
Files with 4,000 lines of code. Variables named data_processed_final_v2. Logic loops that make no sense but "technically work" because the AI hallucinated a workaround.
We are living through the AI Code Hangover. Here is why your "Vibe Coded" app is about to crash, and why you can't just prompt your way out of it.
1. The "Black Box" Problem
When a human writes bad code, there is usually a logic to it. You can ask them: "Why did you do this?" When an AI writes bad code, there is no logic. It is just statistical probability.
I saw a React component last week that had 15 useEffect hooks.
I asked the Junior Dev what they did.
He said: "I don't know. I just kept pasting the error message into Cursor until it stopped crashing."
This is not engineering. This is Whack-a-Mole. The code isn't fixed; the error is just suppressed. And when that code hits production traffic, it explodes. You cannot debug code that nobody understands.
2. The "Boilerplate" Bloat
AI loves to type. It doesn't care about efficiency.
If you ask it to "Process a list," it will write a beautiful, verbose, 50-line function with extensive error handling (that doesn't actually work).
A Senior Human would write a 3-line .map() function.
The Result: Your codebase is 3x larger than it needs to be.
- Larger bundle sizes = Slower load times.
- More lines of code = More surface area for bugs.
- More complexity = Impossible to refactor.
You didn't build a lean startup. You built a bloatware monster.
3. The Security Hallucinations
This is the scary part. AI is trained on the entire internet. That includes bad StackOverflow answers from 2013.
I have seen AI-generated code that:
- Hard-coded AWS keys into the frontend bundle.
- Used
innerHTML(XSS vulnerability) because it was "easier" than sanitizing inputs. - Implemented "Custom Auth" instead of using a library (Never do this).
The AI doesn't know it's insecure. It just knows it satisfies the prompt "Make a login form." If you don't have a Senior Security Engineer auditing every line of AI Slop, you are already hacked.
The Real Numbers: Human vs. Vibe Coder
I tracked the velocity of two teams over 6 months.
| Metric | The "Vibe Coding" Team | The "Senior Human" Team |
|---|---|---|
| Month 1 Velocity | Fast (Shipped 10 features) | Slow (Shipped 2 features) |
| Month 3 Velocity | Slow (Shipped 1 feature, fixed 40 bugs) | Steady (Shipped 4 features) |
| Month 6 Status | Stalled (Codebase is frozen, total rewrite needed) | Accelerating (Clean architecture pays off) |
The Verdict: AI is a credit card. You get the feature now, but you pay 200% interest in technical debt later.
Frequently Asked Questions (That "AI Influencers" Won't Answer)
Should we ban AI tools?
No. That’s luddite thinking. AI is a power tool. In the hands of a Master Carpenter, a nail gun builds a house in half the time. In the hands of a toddler, it causes a hospital visit. The Fix: Only allow Senior engineers to use Copilot. Juniors must write code by hand to learn the fundamentals.
How do we fix a "Vibe Coded" repo?
You can't refactor it. It's usually too tangled. You have to Strangler Fig it. Build a new, clean microservice next to the old one. Slowly migrate traffic over. Do not try to fix the AI Spaghetti; just contain it and kill it.
Is "Prompt Engineering" a real job?
No. It was a 2024 fad. In 2026, the AI models will be smart enough to understand basic English. The value isn't in "Prompting," it's in Evaluation. Can you look at the output and know why it's wrong? That is the only skill that matters.
Leon Staffing places engineers who understand the code, not just the prompt. If you need a team to clean up your AI mess, hire a Senior Architect here.