Vibe Coding Will Get You a Demo. Engineering Will Get You a Business.

Vibe Coding Will Get You a Demo. Engineering Will Get You a Business.

Patrick Farrell

Vibe Coding Will Get You a Demo. Engineering Will Get You a Business. There's a phrase going around right now — "vibe coding" — and it perfectly captures what's wrong with how most people are...

Vibe Coding Will Get You a Demo. Engineering Will Get You a Business.

There's a phrase going around right now — "vibe coding" — and it perfectly captures what's wrong with how most people are building with AI.

Vibe coding is when you throw a prompt at Claude or ChatGPT, get some code back that kind of works, ship it, and move on. It feels productive. It looks impressive in a demo. And it will absolutely fall apart the moment a real user touches it.

Because the details matter. They always have. And AI doesn't change that — it makes it more important than ever.

The Illusion of "Close Enough"

Life has this tempting shortcut built into it: "If I skip a few things, I can still get to where I want to be." And in many areas of life, that's true. You can skip the gym for a week and still be healthy. You can wing a presentation and still get the point across. You can take a shortcut on a road trip and still arrive.

Computers don't work that way. Software doesn't work that way. When you're building systems, "close enough" is the same as "broken."

A function that works 95% of the time fails for 1 in 20 users. An authentication flow that "mostly" handles edge cases is a security vulnerability. A database query that's "pretty fast" becomes a catastrophic bottleneck at scale. An API endpoint that "usually" returns the right data corrupts your entire pipeline the one time it doesn't.

The details aren't nice-to-haves. They're the difference between software that runs a business and software that ruins one.

What "Details" Actually Means

When I say the details matter, I'm not talking about pixel-perfect design or obsessing over variable names. I'm talking about the engineering fundamentals that determine whether your software is reliable, secure, and maintainable:

Security requirements. Are you storing passwords correctly? Is your API authenticated? Are you validating input on the server side, not just the client? Are you handling API keys securely — not hardcoded in your repository? Have you thought about SQL injection, cross-site scripting, CSRF tokens? Every one of these is a detail. Every one of them matters. And AI will cheerfully generate insecure code if you don't specifically ask it not to.

Data handling. Where is your data hosted? Is it encrypted at rest and in transit? Do you have backups? Do you have a plan for what happens when — not if — something goes wrong? Are you compliant with the regulations that apply to your users' data? These aren't exciting questions. They're the questions that determine whether your business survives its first incident.

Authentication and authorization. OAuth flows. Token refresh cycles. Session management. Role-based access control. These systems are complex because they have to be. Getting authentication "mostly right" means getting security completely wrong. Every auth flow has edge cases, and each one is a potential breach if you haven't handled it explicitly.

Execution time and performance. How long does an operation take? Is that acceptable for your users? What happens when ten people use it simultaneously? A hundred? A thousand? Have you indexed your database queries? Are you caching what should be cached? Are you loading resources efficiently? Performance isn't optimization — it's functionality. Slow software is broken software.

Error handling. What happens when something fails? Not "what should happen in the ideal case" — what actually happens when the API returns a 500, when the database connection drops, when the user submits data you didn't expect? Robust error handling is invisible when it works and catastrophic when it's missing.

Repeatability. Can someone else deploy this? Can it be rebuilt from scratch? Does it run the same way on a different machine? If you can't reproduce your system reliably, you don't have infrastructure — you have a house of cards.

AI Doesn't Handle the Details for You

Here's what most people get wrong about building with AI: they treat it like a senior engineer who's going to think of everything. It isn't. It's an incredibly fast, incredibly capable builder that will construct exactly what you ask for — including every flaw in your specifications.

If you don't ask for input validation, you won't get it. If you don't specify error handling, it'll build the happy path and nothing else. If you don't mention security, the code will work perfectly — and be completely vulnerable.

AI is a power tool, not a thinking tool. A power saw cuts faster than a hand saw, but it doesn't decide where to cut. That's still your job. And if you don't know where to cut — if you don't understand the details of what you're building — the power tool just lets you make mistakes faster.

This is the fundamental difference between vibe coding and engineering with AI:

  • Vibe coding: "Build me a login page." Ship it. Move on.
  • Engineering: "Build me a login page with bcrypt password hashing, rate limiting on failed attempts, CSRF protection, secure session cookies with HttpOnly and SameSite flags, input sanitization on both fields, and proper error messages that don't leak whether the email exists in the system." Review it. Test it. Then ship it.

Same tool. Same AI. Completely different outcomes. The difference is the person directing the AI — and whether they understand the details.

The Checklist You're Probably Skipping

Before you ship anything built with AI, ask yourself:

  • Did I review what AI generated? Line by line. Not a quick scroll — an actual review where you understand what every piece does and why.
  • Is it secure? Authentication, authorization, input validation, data encryption, secret management. Not "probably secure" — verifiably secure.
  • Does it handle failure? What happens when the network drops? When the database is slow? When the user does something unexpected? Test the unhappy paths, not just the happy one.
  • Is it repeatable? Can this be deployed from scratch? Is it documented? Will it work the same way in six months when you've forgotten how you built it?
  • Does it perform? Under real conditions, with real data, at real scale. Not just with the three test records in your development database.
  • Would I trust this with someone else's data? Because that's exactly what you're doing when you ship it.

If you can't answer yes to all of those, you're not done. AI built the first draft. Now do the engineering.

Your Users Expect You to Handle This

Here's the reality that should keep every builder honest: the person using your tool doesn't know — and shouldn't have to know — what's happening underneath.

They expect the login to be secure. They expect their data to be private. They expect the system to be fast. They expect it to work on Tuesday the same way it worked on Monday. They expect that when they click "submit," something correct happens on the other end.

They're not thinking about OAuth token refresh cycles or database indexing or input sanitization. That's your job. You handling those details is what they're paying for — whether they know it or not.

And when you skip those details? They don't see the missing security header. They don't notice the unhandled error state. They just wake up one morning to find their data leaked, their account compromised, or your service down — and they leave. Quietly and permanently.

Engineering With AI Is Still Engineering

The AI era didn't eliminate the need for engineering discipline. It amplified it.

When you could only build as fast as you could type, the scope of your mistakes was limited. Now that AI can generate thousands of lines of code in minutes, the scope of your mistakes is unlimited — unless you bring the engineering mindset that catches them.

Think of it this way: AI gives you the power to build a skyscraper in a day. But if you don't understand structural engineering, you're just building a very tall pile of debris. The speed is only valuable if the foundation is solid.

Handle the details. Review the code. Test the edge cases. Secure the endpoints. Validate the inputs. Monitor the performance. Document the system. Make it repeatable. Make it reliable. Make it something you'd trust with your own data.

That's not the boring part of building with AI. That's the part that separates demos from businesses, prototypes from products, and vibe coders from engineers.

The details are where the real value lives. Don't skip them.