Rubber duck debugging, but the duck talks back

There is a rubber duck on half the desks in my office. It is not a mascot. It is a debugging tool, and a surprisingly effective one. When you are stuck on a bug, you pick up the duck and explain your code to it, line by line, out loud. Somewhere around line fourteen you hear yourself say something that is obviously wrong, and you put the duck down and fix it.

The technique is old enough to have a name, rubber duck debugging, and it works because explaining forces you to slow down. In your head you skip steps. Out loud, to an audience that knows nothing, you cannot. The duck’s great strength is that it knows nothing and says nothing.

Now the duck has opinions

In the last two years the duck has learned to talk. Most programmers I know now paste their broken code into an AI assistant and describe the problem. The assistant answers instantly, often correctly, and sometimes with enormous confidence about something that is completely wrong.

This is useful. I use it every day. But it is not the same thing as the duck, and I think we have lost something in the swap without noticing.

The duck worked because it never interrupted. The new ducks interrupt constantly.

What the silent duck was really for

The silent duck did not solve your problem. It made you solve it. Every bug you fixed with the duck left you understanding your own code a little better. The fix came from your head, so it stayed there.

A talking duck gives you the answer before you have finished asking. That is wonderful when you are tired and the bug is boring. It is less wonderful when the bug is telling you something important about how your system works, and you paste the fix without ever hearing the message.

How I use both

• For boring bugs, like a typo, a missing import or a wrong date format, I ask the talking duck and move on.

• For confusing bugs, I explain it to the plastic duck first, for five full minutes, before I type anything.

• If I still do not understand it, I ask the talking duck to explain the bug, not to fix it.

• I never paste a fix I could not explain back to the plastic duck.

That last rule has saved me more than once. The talking duck is brilliant and fast and occasionally invents things. The plastic duck is slow, silent and has never been wrong, because it has never said anything at all.

A duck for every desk

We gave every new hire on our team a rubber duck this year, alongside their laptop. It is a joke, and it is not a joke. The duck is a reminder that the most powerful debugging tool you own is the part of your brain that switches on when you have to explain yourself.

The new ducks can talk. That is fine. Just make sure you are still doing some of the talking.