An app testing group is called a quality assurance team, or QA team

When software developers finish writing code for an app or website, they hand it to a quality assurance team — usually called a QA team — to find problems before real people use it. The QA team's job is to break things on purpose: they run the app through thousands of scenarios, try to crash it, test it on different devices, and look for bugs that the developers missed.

The term "quality assurance" describes the whole process of checking that software works the way it should. You'll also hear people say "QA testing," "QA engineers," or just "the QA team." Smaller companies might call the same role a "test engineer" or "software tester." The name changes, but the work is the same: find what's broken before customers find it.

Key Takeaways

  • A quality assurance team, or QA team, is the group that tests apps and websites for bugs and problems before they reach users.
  • QA teams use both automated testing (running the same tests over and over with code) and manual testing (a person clicking through the app by hand).
  • QA testing happens at different stages: unit testing checks small pieces of code, integration testing checks whether pieces work together, and user acceptance testing checks whether the finished product does what customers actually need.
  • A QA team can catch problems like crashes, slow performance, security holes, and features that don't work as designed.

How QA teams find problems

QA teams use two main approaches: automated testing and manual testing. Automated testing means writing code that runs the same tests thousands of times without a person watching — checking that a login form accepts the right passwords, that a payment button charges the right amount, that a search function returns results. Manual testing means a person sits down with the app and tries to use it the way a real customer would, looking for anything that feels wrong or broken.

Most QA teams do both. Automated tests catch obvious failures fast and run constantly as developers add new code. Manual testing catches things automation misses: a button that's hard to find, text that's confusing, a feature that works technically but doesn't make sense to use. A QA engineer might spend an afternoon trying to break a new feature in every way they can think of — entering bad data, using the app on a phone instead of a computer, switching between features in unexpected orders.

Different types of testing at different stages

Unit testing happens first, often by the developers themselves. They test tiny pieces of code in isolation — does this function add numbers correctly, does this button respond to a click. Integration testing checks whether those pieces work together — when the login code talks to the database code, does the user actually get logged in. System testing checks the whole app working together. User acceptance testing, or UAT, is the final stage where real customers or a test group of customers try the app and say whether it actually does what they need.

Each stage catches different problems. Unit testing finds coding mistakes. Integration testing finds problems where different parts of the code don't communicate right. System testing finds performance problems — the app works, but it's slow. User acceptance testing finds problems nobody thought of — the app does what the spec said, but customers don't want to use it that way.

What QA teams look for

QA teams test for functional bugs — features that don't work at all or work wrong. They test performance — does the app slow down when thousands of people use it at once. They test security — can someone break in and steal data. They test compatibility — does the app work on an iPhone and an Android phone, on a new computer and an old one, on fast internet and slow internet.

They also test usability — can a normal person figure out how to use the app without getting lost, or is the design confusing. They test accessibility — can someone who is colorblind or deaf or uses a screen reader still use the app. A good QA team thinks about edge cases: what happens if someone enters their password wrong ten times, what happens if they close the app in the middle of a transaction, what happens if they use the app in a language it wasn't designed for.

Why companies have QA teams instead of just shipping code

Developers are good at writing code, but they're often bad at breaking it — they know how the code is supposed to work and they use it the way they intended. A QA team comes in fresh and tries to use the app the way a confused customer would. They find problems that would cost the company money if customers found them first: a bug that crashes the app loses users, a security hole loses trust, a slow feature loses sales.

For apps that handle money or health information or safety-critical systems, QA testing is not optional — it's required by law. For consumer apps, a bad experience spreads fast through reviews and social media. A QA team's job is to make sure the app works well enough that people want to use it and tell their friends about it.

QA roles and titles you might see

A QA engineer or QA analyst is someone who designs tests and runs them, either by hand or by writing test code. A test automation engineer specializes in writing code that tests code. A QA lead or QA manager oversees the team and decides what gets tested and when. A quality assurance director sets the overall testing strategy for a whole company.

Some companies hire beta testers — real customers who use a nearly-finished app and report problems. Others hire user acceptance testers who represent the actual people who will use the product. The titles vary, but they're all part of the same mission: find problems before customers do.

Frequently Asked Questions

Is QA testing the same as debugging?

No. Debugging is what developers do when they find a problem — they read the code and fix it. QA testing is finding the problems in the first place. A QA team finds the bug; the developer debugs it.

Can developers test their own code instead of having a QA team?

Developers test their own code during development, and that's important. But developers know how the code is supposed to work, so they test it the way they intended. A QA team tests it the way confused users will, which catches different problems. Most companies use both.

What's the difference between QA and customer support?

QA finds problems before customers see them. Customer support helps customers when they run into problems after the app ships. QA prevents problems; support handles the ones that slip through.

How long does QA testing take?

It depends on the app's size and complexity. A small update might take a few days. A brand new app might take weeks or months. QA testing usually takes 20 to 40 percent of the total time to build an app.