Users test your code

In a session on introduction to testing (not testers), I simplified my story to having two kinds of testing:

• Your pair of eyes on seeing problems
• Someone else's pair of eyes on seeing problems

My own experience in 99% of what I have ended up doing on my 25-year is that I'm providing that second pair of eyes, and working as that has made me a tester by profession.

Sometimes the second pair of eyes spend only a moment on your code as they are making their own changes adding features (another developer) and you do what you do for testing yourself. Sometimes it becomes more of a specialty (tester). And while the second pair of eyes often is used to bring in perspectives you may be lacking (domain knowledge), there is nothing preventing that second pair of eyes having as strong or stronger programming knowledge that you do. 

You may not even notice your company has second pair of eyes, as there's you and then production. Then whatever you did not test gets tested in production, by the users. And it is only a problem if they complain about the quality, with feeling strong enough to act. 

To avoid complaining or extensive testing done slowly after making changes, modern developers write tests as code. As any second pair of eyes notices something is missing, while adding that, we also add tests as code. And we run them, all the time. Being able to rely on them is almost less of a thing about testing and quality, and more of a thing about peace of mind to move faster. 

In the last year or so, my team's developers have gotten to a point where they no longer benefit from having a tester around - assuming a non-programmer tester covering the features like a user would. While one is around, it is easy to not do the work yourself, creating the self-fulfilling prophecy of needing one. 

Over an over again, I go back to thinking of one of my favorite quotes:

"Future is already here, it is just not equally divided"

I believe future is without testers, with programmers co-creating both application software and software that tests it. I believe I live at least one foot in that future. It does not mean that I might not find myself using 80% of my time testing and creating testing systems. It means that the division is more fluid, and we are all encouraged to grow to contribute beyond our abilities of the day.

The past was without testers but also without testing. To see the difference of past and future, you need to see how customer perceives value and speed. Testing (not testers) is the way to improve both.