Someone recently posed this question in a Slack channel at work: “why pay for vended software that we can build ourselves now that we have the tools?”  They asked this question in the context of Claude Code being made generally available for internal use.  It's a fair question on the surface. These tools can be expensive, sometimes frustrating, and the capabilities of modern LLMs are genuinely impressive. But the growing power of Gen AI doesn't fundamentally change the buy-versus-build decision — here’s why.

 

Vibe coding is not a production strategy.

Yes, you can prototype a Salesforce-like CRM or a Slack-like messaging tool in a weekend with the right AI assistant. But if your business is going to depend on it, you're not just building a demo. You're committing to building, deploying, and maintaining something production-grade — with all the architectural decisions, security concerns, and UI considerations that entails. GenAI may accelerate parts of that process—but it doesn't eliminate any of them.

 

Now do the math on the opportunity cost.

Building your own internal replacement for a third-party SaaS product isn't a one-engineer side project. It's multiple engineers, sustained over time, making real decisions about infrastructure, reliability, and scale. That means:

  • Salaries and benefits for the team dedicated to this effort
  • Switching costs to migrate off whatever you're currently using
  • Ongoing maintenance — because software doesn't maintain itself

 

And critically: every hour those engineers spend building your proprietary version of Slack or ServiceNow is an hour they're not spending on the software that is actually core to your business.  What advances are your competitors making at your expense because they’ve fully dedicated their people to improving their core business functionality and bought tools that are tangential but helpful?

 

That's the real question to ask.

Is replacing a third-party tool — one that entire companies exist to build and support — actually a better use of your engineering talent than investing in the capabilities that differentiate your product in the market?

For most companies, in most cases, the answer is no. Gen AI is a powerful accelerant. But it doesn't change the fundamental logic of what's worth building versus what's worth buying.