What should businesses look for when hiring iOS app developers for their mobile proje

I'm currently researching how businesses can choose the right iOS app developers for building high-quality and scalable mobile apps. With so many development companies and freelancers available, it’s hard to know who truly delivers. What key skills, experience, or traits should companies prioritize? Also, if anyone has experience working with firms like TechGropse, I'd love to hear your insights or recommendations!