According to [AppsFlyer 1 in every 2 apps installed are uninstalled within 30 days. That means you have a really short time period to impress your users before they abandon your app and try something else. So you need to be delivering functionality and quality - right from the start.
You could rely on the development team to test as they go along, but that only takes time away from their work. That’s not to say they aren’t involved - after all, code quality will impact the product. Instead, it’s time to add a dedicated QA (quality assurance) team to the software engineering process.
But, sometimes, in the busy periods of release cycles and new updates, the user can get lost among the noise. You might get so tied up checking non-functional requirements that you forget about the importance of the user interface and user requirements. Or maybe you’ve been so caught up in the details, you’ve lost track of the big picture and forgotten that portability and privacy need to be factored in.