I Built the Same Feature Twice. Once With the Agent. Once By Hand. The Numbers Surprised Me.

Not a complex feature. A settings panel with validation, save states, and error handling.

Agent version: 40 minutes to generate, 90 minutes to fix, 30 minutes to test. Total: 2 hours 40 minutes.

By hand: 3 hours to write, 20 minutes to fix, 15 minutes to test. Total: 3 hours 35 minutes.

The agent was faster. But the gap was not as wide as I expected. And the by-hand version had fewer edge cases I hadn't thought of. Not because I'm a better coder. Because writing it myself forced me to think through every branch before it existed.

The agent generated code fast and I debugged fast. But I was debugging things I would have caught before they happened if I had written them myself.

I still use the agent. But I've started asking a different question. Is this the kind of feature where speed matters more than understanding?

What's the last feature you built both ways? And which one did you keep?