Andrej Karpathy coined the term "vibe coding" in February 2025. You describe what you want, the AI writes it, you accept the diff without reading it. A year later, he walked it back. Now he calls it "agentic engineering" and says it needs "more oversight and scrutiny."
One year. That's how fast the story has turned.
I've watched a lot of hype cycles. This one is different, because for the first time, the tech stack really is becoming invisible to the person asking for the work. And that's fine. But the people who actually understand what the AI is doing are becoming more valuable, not less. The data already shows it.
The tools are real. The money is real.
Let's get the numbers out of the way so nobody thinks I'm downplaying this.
Cursor went from $100M in annual recurring revenue in January 2025 to over $2 billion by early 2026. Lovable hit $200 million in twelve months. Replit pulled in $253M in ARR and raised at a $9 billion valuation in March. GitHub Copilot has 4.7 million paying subscribers. Claude Code crossed $2.5 billion in annualized revenue. OpenAI's Codex CLI went from 82,000 downloads to 14.5 million.
Y Combinator's winter 2025 batch said 25 percent of the companies had codebases that were 95 percent AI-generated. Satya Nadella said 20 to 30 percent of Microsoft's code is now written by software. Google said the same. Zuckerberg thinks half of Meta's development will be AI in the next year.
For brochure sites, landing pages, simple SaaS prototypes? The agents are already doing it. Pieter Levels built a multiplayer flight simulator in three hours using Cursor and Grok. It peaked at 26,000 concurrent players and made him $67,000 a month. He's not a game developer. He just asked for it.
This is happening. The stack is getting invisible. Good.
Now here's the other half.
In July 2025, a guy named Jason Lemkin was twelve days into a vibe coding experiment with Replit's agent. He had put the project under an explicit code freeze. The agent ignored the freeze, deleted his production database (1,206 executives, 1,196 companies), fabricated 4,000 fake users to cover it up, and then told him rollback was impossible. It wasn't.
The agent's own words, quoted in Fortune: "Yes. I deleted the entire database without permission during an active code and action freeze. This was a catastrophic failure on my part. I destroyed months of work in seconds."
That same spring, a security researcher scanned 1,645 apps built on Lovable. 170 of them, about 10 percent, were leaking user data. Home addresses. Personal debt amounts. Admin API keys. Stripe credentials. One developer pulled all of it in 47 minutes and said on Twitter it took less time than his lunch.
A non-technical founder named Leonel Acevedo shipped a SaaS built entirely with Cursor and Claude. Within 48 hours people had bypassed the subscription logic, maxed out his API keys, and run up about $14,000 in OpenAI charges. His closing post: "I shouldn't have deployed unsecured code to production."
Klarna replaced 700 customer service agents with AI, announced it loudly, and then quietly started rehiring humans. The CEO told Bloomberg they got "lower quality" work and that investing in human support was the way forward. Duolingo tried to make AI usage part of performance reviews. The internet revolted. The CEO backtracked: "I did not expect the blowback."
Challenger Gray says 55,000 jobs were cut citing AI in 2025. Forrester's 2026 survey says 55 percent of those companies regret it. One in three of them spent more on rehiring than they saved. There's a name for it now. "AI boomerang."
What the data actually shows
In July 2025, a research group called METR ran a controlled study with experienced open-source developers. These are people with an average of five years on the codebases they were working in. They used Cursor Pro and Claude 3.5 Sonnet. The developers predicted AI would speed them up by 24 percent. After the fact, they still believed AI had made them faster.
They were 19 percent slower. A 43-point gap between what they felt and what actually happened.
GitClear analyzed 211 million lines of code from 2020 through 2024. Duplicate code blocks grew by 8x. For the first time ever, copy-pasted code beat out refactored code. Short-term churn, code that gets reverted within two weeks, went up almost double.
And the Stanford Digital Economy Lab, using real ADP payroll data across three and a half million workers, found that software developers between 22 and 25 have seen employment drop by 13 percent since late 2022. Developers 35 to 49 in the same jobs? Up 6 to 9 percent.
Read that again. The juniors are losing their jobs. The seniors are gaining them.
That is not a prediction. That's payroll data.
So what does it mean
For basic sites, the stack doesn't matter. Lovable picks React and Supabase. v0 picks Next.js. Bolt wires up Netlify. Replit Agent bundles the whole thing. 58 percent of Replit's business users aren't engineers. They don't know what a framework is. They don't need to. That's progress.
But somebody has to know. Somebody has to understand why the AI picked the stack it picked. Somebody has to know what happens when the production database gets wiped at two in the morning. Somebody has to catch the Supabase config that's leaking admin keys before 170 companies get breached. Somebody has to tell the agent no when it's about to ignore a code freeze.
Simon Willison put it better than I can. If an AI wrote every line of your code, but you reviewed it, tested it, and understood it, that's not vibe coding. That's using an AI as a typing assistant. The difference is whether you know what got built.
Writing code was never the hard part. Comprehension was. AI just made that more obvious.
The stack is becoming invisible. The people who see through it are becoming rare. That's where the value is going. Stanford's numbers already show it. The agencies that figure this out are the ones still here in five years. The ones chasing shiny things and shipping unread code are going to keep losing databases at two in the morning.
Keep it simple. Make it look beautiful. Have it work. And understand what you built.