I Thought I Was a Developer. I Was Just Retesting.

Every change meant retesting

👋 Hello, this is Valentina with the free edition of the Optivem Journal. I help Engineering Leaders & Senior Software Developers apply TDD in Legacy Code.

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I thought software development meant building things.

Then I got my first job.

And most of my time wasn’t building.

It was retesting.

Fix something → test it
Add something → test it
Change something small → test everything again

The system felt fragile.
Like it was waiting to break.

No one called it “testing”—I was a developer, after all.
But in reality, I was running the same manual checks again and again just to feel confident enough to move forward.

It was exhausting.

The first breakthrough

Then I discovered unit tests.

Write the test once → run it forever.

No more clicking through the same flows.
No more guessing what broke.

If something failed, I knew exactly where.

It felt like I finally unlocked “real” development.

Everything passed. Things still broke.

But then something didn’t make sense.

All my tests were passing.

And production bugs…
weren’t really going down.

That was the confusing part.

If everything was “tested”…
why were things still breaking?

Here’s what I was missing:

Unit tests tell you that pieces of your system work.

They don’t tell you that the system works.

You don’t ship code. You ship behavior.

You can have 100% unit test coverage…
and still ship a broken feature.

Because users don’t interact with your classes.

They interact with behavior.

That’s what led me to acceptance tests.

Tests that don’t care how the code works (you can write them even if your code is a Ball of Mud)—
only whether the system behaves correctly from the outside.

Like a user would experience it.

Because in the end:

You don’t ship code.
You ship behavior.

See It in Practice

Want to see how acceptance tests can save you time, frustration, and endless bug loops? I’m running a hands-on Acceptance Testing Workshop on May 25–26 (4 hours).

Limited spots. Register now - 100 EUR off with code DISCOUNT_100