Causation vs Correlation: The Illusion of Control in a World of Signals

Software is predictable. At least, that’s the illusion.

You write code. You run it. It works (hopefully). You ship it. The system responds. Something changes: a spike in traffic, a drop in latency, an influx of logs.

And naturally, you tell yourself: “This happened because I did that.”

But pause. Zoom out. How often is that actually true?

How often are we simply narrating stories after the fact, finding patterns in the noise, drawing arrows between events that never actually touched?

We crave causality. It gives us control.

Humans, and yes, developers too, are narrative-driven creatures. Causation is comforting. “X caused Y” feels like power. Like mastery. Like truth.

But correlation is sneaky. It mimics causation with just enough rhythm to fool us.

That CPU spike after your deploy? Could be your code. Or a misbehaving cron job. Or the fact that it’s Friday and traffic patterns always shift before the weekend.

Code is logical. Systems are not.

In a pure function, cause and effect are clean. But once you step into distributed systems, observability stacks, flaky dependencies, and 3 AM deploys, causality gets murky.

Logs don’t always tell the full story. Metrics lag. Dashboards lie by omission.

You’re not debugging a machine. You’re reading a diary written by a dozen unreliable narrators, each with their own timezone and context.

Philosophers asked this long before devs did

David Hume questioned whether we can ever know cause, or if we just see one thing follow another, over and over, and assume a link.

He'd probably look at our Grafana dashboards and laugh.

So maybe the better question isn’t “What caused this?” but:

In the end, we debug life like we debug code

We watch for patterns. We try to trace the root. But sometimes, all we see is a ripple in the logs, a shadow, not the source.

The lesson?

Be humble. Be skeptical. And when in doubt, test.

Because in code, as in life, mistaking correlation for causation isn’t just a bug. It’s a worldview glitch.