Unit tests prove that each piece of code does what its developer intended. They cannot prove that the product works for a person on a cheap phone, on a train, who taps the back button at the worst possible moment. That is what a QA pass is for.
Real devices
Simulators do not run out of memory, overheat or have a notch in the wrong place. We test every release on a small set of real phones, including at least one older, slower model.
Bad networks
We throttle the connection, drop it mid-request and switch between Wi-Fi and mobile data. Loading states, retries and offline messages only get tested when the network misbehaves on purpose.
- Slow 3G and offline on every key screen
- Requests interrupted halfway through
- App sent to the background during a payment or upload
Odd user paths
Real users double-tap submit buttons, paste emoji into phone fields and come back to a form three days later. Exploratory testing follows those paths deliberately, because nobody writes unit tests for them.
Most launch-day bugs are not in the code anyone was worried about. They are in the paths nobody thought a user would take.
- QA
- Testing
- Release
