When I started my career as a developer, I had a very clear picture in mind: I would build features and create things that deliver value to users. To be honest, what we call “testing” always felt like something that comes after development — something that has to be done, but not particularly exciting.
Then I started working at a testing company.
At first, I didn’t think it would feel that different. After all, I was still writing code. But in a short time, I realized that I wasn’t actually doing the same job anymore. Or more accurately, I was doing the same job with a completely different mindset.
Back then, when I built a feature, the first question I asked myself was simple:
“Does it work?”
Does the button navigate? Does the API respond? Does the screen open? Okay, done — ship it.
But in this new testing-focused world, that question suddenly felt insufficient.
I found myself, almost unconsciously, asking different questions:
“Where could this system break?”
“What happens if the user does something unexpected here?”
“What will the user see if the API is slow… or doesn’t respond at all?”
To be honest, this shift was exhausting at first. Because it was no longer enough to build something that simply works. I had to think more, consider more scenarios, and account for more possibilities. At times, it even felt like this was slowing me down — and that was stressful.
But then I realized something:
The time I thought I was losing was actually time I would gain back many times over.
I remembered those all-too-familiar moments:
500 errors crashing the system in the middle of the night, frustrated users unable to log in, entire user flows breaking because of a tiny UI bug…
In those moments, while debugging under pressure, there was one undeniable truth:
I had never thought about those scenarios in the first place.
After working in a testing-focused environment, my perspective on these issues completely changed. Instead of asking, “How did this slip through?” I started asking, “Why wasn’t this considered from the beginning?”
And then something interesting happened:
I started catching bugs before they even occurred.
While writing code, certain things began to stand out. The parts I thought “this might cause issues later” often did — unless I fixed them beforehand. My code became cleaner, less fragile. My debugging time decreased. In some cases, there was nothing left to debug, because the problem never happened.
And the most surprising part?
I wasn’t actually working slower. On the contrary, I was faster overall — because I was doing things right from the start instead of fixing them later.
Working as a developer in a testing company taught me this:
Software development is not just about making something work — it’s about making sure it works under all conditions.
Now, when I build something, saying “it works” is no longer enough.
I need to ask, “Is it reliable?”
And I think that’s the biggest shift.
Because at some point, you realize that we’re not just writing lines of code — we’re building trust with the user.
And once you gain that perspective, there’s really no going back.
Remember:
The best developers are not the ones who know how software works but the ones who understand how it can break.