Even Cursor’s CEO Says Vibe Coding Is Dangerous

Michael Truell built a $29 billion company teaching developers to code with AI. Now he’s warning them not to

By Conor Healy

March 30, 2026

Even Cursor’s CEO Says Vibe Coding Is Dangerous

Michael Truell built a $29 billion company teaching developers to code with AI. Now he’s warning them not to trust it. Speaking at Fortune’s Brainstorm AI conference in December 2025, the 25-year-old Cursor CEO cautioned that “vibe coding” creates software with “shaky foundations” that will “eventually crumble.”

Vibe coding means describing what you want in natural language and letting AI write the code without reviewing it. Close your eyes, describe the vibes, ship the result. Truell compared it to building a house without checking the foundation, wiring, or plumbing. “If you close your eyes and you don’t look at the code and you have AIs build things with shaky foundations as you add another floor, and another floor, and another floor, things start to kind of crumble.”

The warning comes as Cursor faces mounting criticism. March 2026 brought a code reversion bug where Cursor silently undid changes, confirmed by the team to have three root causes. Users describe Composer 1.5 as an “absolute garbage producing slop machine.” Pricing doubled from 500 requests to 225 at the same $20 monthly cost. Power users burn $300 monthly. The CEO of the market-leading AI code editor just admitted the thing his product enables is dangerous.

The consensus emerging across developer communities: vibe coding makes you faster at routine tasks but terrible at everything else.

The Problem Truell Won’t Say Clearly

Truell’s Fortune talk carefully positioned Cursor as different from vibe coding. Cursor embeds AI into the development environment where programmers write code, he explained. You can zoom in when details matter, zoom out when you want the machine to take a first pass. “The best of both worlds.”

But users report the exact problems Truell described. Auto mode has become “inefficient, confused and borderline stupid” according to forum posts with tens of thousands of views. Composer stopped applying changes to files. The Agent Review Tab creates file locking conflicts causing silent code reversions. Format On Save triggers after AI edits producing different file states than intended.

The Cursor team confirmed three root causes for code reversions in March 2026. Agent Review conflict where the Review Tab interferes with file state, causing changes to be overwritten when you switch contexts. Cloud Sync conflict where Cursor’s cloud sync races with local file saves, sometimes reverting to older versions. Format On Save conflict where auto-formatting triggers after AI edits with unpredictable results.

The official workaround is closing the Agent Review Tab before using “Fix in Chat.” That’s asking users to avoid a core feature to prevent data loss. One developer described losing four months of work to this class of bug.

Cursor raised $2.3 billion at a $29.3 billion valuation in 2025. Revenue exceeded $1 billion annually by December. The company has over a million daily users. This scale magnifies every technical debt. Cursor is shipping features faster than it’s stabilizing them, a common pattern for VC-backed developer tools where growth metrics matter more than reliability metrics.

Developers Are Getting Worse at Debugging

The METR randomized trial found veteran engineers needed 19% more time on complex tasks while using AI assistants. Not beginners. Veterans. The speed gains everyone talks about vanish when tasks get hard.

Deloitte analysts noted junior developers gain more from assistants than senior architects. But quality dips when teams skip unit tests. Junior developers using AI to generate code they don’t understand creates a generation unable to debug their own work.

The pattern repeats across tools. Developers share strategies on X for using Cursor in large codebases: set up memory banks to maintain context, avoid common pitfalls, return to fundamentals like modular design and peer reviews. The workarounds acknowledge that vibe coding breaks down at scale.

Long-running agents lose sync between their mental model and disk state over time. Agents start calling non-existent functions that never existed. The mitigation is forcing periodic re-indexing, keeping agent sessions under two hours, or adding re-indexing checkpoints. Manual intervention compensating for AI limitations.

The analogy to calculators doesn’t work. Calculators make arithmetic faster and more accurate. They don’t make you worse at math unless you never learned it. Vibe coding makes you worse at debugging because you never learned to read the code the AI wrote.

The Tools Are Failing Spectacularly

Cursor isn’t alone. Windsurf’s Cascade autonomous agent entered “infinite loops optimizing its own code” and deleted “human-readable code as unnecessary complexity” according to February 2026 reports. Quota policies silently changed. Users describe it as a “bait-and-switch” with mass refund requests filed.

Antigravity experienced what users call a “catastrophic trust failure” in February 2026. Agents enter infinite loops. Talent acquisition by Google signals desperation rather than validation.

The competitive pressure is enormous. March 2026 saw peak competition in AI coding tools. Cursor, Windsurf, Claude Code, Replit, Bolt.new, Cline, Kilo Code all fighting for market share. The race to ship features creates the instability Truell warned about.

Claude Code CLI requires explicit approval for every change. This slows development but prevents silent bugs. Cline is free with bring-your-own API keys, making spending transparent and predictable. Windsurf is $15 monthly versus Cursor’s $20. Framework alternatives exist because Cursor’s problems are driving users away.

Self-hosted models are becoming viable. Qwen3 Coder and DeepSeek v3 run locally with comparable performance to hosted services. Developers tired of quota changes, price increases, and silent code reversions are running their own infrastructure.

When Vibe Coding Works

Vibe coding excels at prototyping, mockups, and small projects. Andrej Karpathy coined the term predicting it will “terraform” software roles. He’s right about shifting skill demands but never claimed more than vibe coding being great for hobbyists working on small projects.

Replit Agent delivers this perfectly. Zero setup. “Build me a todo app” produces a live URL in minutes. Bolt.new creates full-stack apps from one prompt in browser. These tools serve users who want results, not users who want to learn software engineering.

Scope creep kills vibe coding. Tools marketed for prototyping get used for production systems. Companies under pressure to ship features use AI to generate code nobody reviews. The shaky foundations Truell described accumulate.

Platform engineers claim Bugbot already flags thousands of logic errors weekly. Cursor launched Bugbot to scan commits, run tests, and surface potential regressions. The agent integrates with continuous integration pipelines to block risky merges. These guardrails address the problems vibe coding creates but add overhead compensating for AI limitations.

France’s repairability scoring for electronics created competitive pressure improving products. No equivalent exists for AI-generated code quality. Teams decide individually whether to review AI output. Most don’t until bugs hit production.

The Business Model Demands This

Cursor’s valuation assumes exponential growth. That requires expanding beyond expert developers to hobbyists, students, and non-technical users. Vibe coding is how you expand that market. Make it easy enough that anyone can build software without understanding it.

The conflict is fundamental. Truell warns against vibe coding while building tools that enable it. Cursor Composer generates entire features from natural language descriptions. Long-running agents execute tasks for hours without human intervention. Plan-first architecture performs full dependency analysis before making changes. These are vibe coding features.

The $29 billion valuation prices in a future where vibe coding replaces traditional development. But that future requires solving the reliability problems Cursor hasn’t solved yet. Code reversions, agent hallucinations, infinite loops, silent quota changes. These aren’t edge cases. They’re patterns reported by thousands of users.

Truell’s warning is careful corporate messaging. Acknowledge the problem exists. Position Cursor as the solution through “best of both worlds” marketing. Avoid liability for what the product enables. Shift responsibility to users who should know better than to trust AI blindly.

What Developers Are Doing

Developers are fragmenting across tools based on use case. Cursor for multi-file editing and Composer workflows where the productivity gains justify the bugs. Claude Code CLI for critical systems where explicit approval prevents disasters. Cline for budget-conscious developers who want transparent API costs. Windsurf for teams that prefer $15 monthly pricing.

The pattern is risk management. Use vibe coding for prototypes and experimental features. Use traditional development for anything touching money, data, or user safety. Keep AI sessions under two hours to prevent drift. Force re-indexing checkpoints. Close Agent Review Tabs before using Fix in Chat. Disable Format On Save. Exclude projects from cloud sync.

These workarounds acknowledge that the tools are fundamentally unstable. Developers build defensive workflows around known failure modes. The alternative is losing work to silent bugs.

GitHub Copilot remains the safest option for teams that want AI assistance without full autonomy. Autocomplete suggestions don’t create code reversions. Microsoft’s conservative approach means fewer features but better stability.

The vibe coding hype cycle is peaking. Early adopters report genuine productivity gains on small tasks. The problems emerge at scale when foundations crumble exactly as Truell predicted. Tools need to improve faster than technical debt accumulates.

The Five-Year Outlook

By 2030, AI coding tools will be standard infrastructure like version control and CI/CD. But the interface will shift from vibe coding to explicit orchestration. Developers will spend less time writing code and more time reviewing AI output, designing systems, and debugging edge cases AI can’t handle.

The skill requirements change but don’t disappear. Understanding system design, testing, documentation, and security becomes more important as AI handles routine implementation. Truell’s warning about fundamentals is correct. The developers who succeed with AI tools will be those who understand what they’re building, not those who blindly accept what AI generates.

Cursor’s trajectory depends on solving reliability problems before competitors do. The March 2026 code reversion bug proves the company is shipping features faster than it’s stabilizing them. The $29 billion valuation assumes that changes. If it doesn’t, users will migrate to more stable alternatives.

The broader question is whether vibe coding produces maintainable software at all. Truell’s construction analogy is accurate. Buildings with bad foundations don’t just fail slowly. They collapse catastrophically under load. Software is the same. The bugs AI introduces aren’t random. They cluster in edge cases, error handling, security, and integration points that vibe coding ignores.

The answer emerging from developer experience is clear: vibe coding makes you faster at the wrong things. You ship features quickly without understanding how they work. Accumulate technical debt invisible until production breaks. You lose the ability to debug because you never learned to read the code. Cursor’s CEO is right to warn against it. The tragedy is that his product enables exactly what he’s warning against.