But, 'ready for production' is a relative term that must be considered in context. Apple is encouraging developers to submit apps with Swift, so clearly they think it's 'ready for production' in some contexts.
If you're building an app for which an obscure, swift-specific bug may cause a critical security or safety issue for your customers then perhaps go with objective-c to sleep better at night. Although my impression is that Swift is stable enough even for this category of apps.
But, I'd wager that vast majority of apps out there do not fall under that category.
Agreed on excuse. But if the vendor doesn't have people already familiar it might be worth asking whether it's worth paying for them to learn it if you don't already have an existing codebase that requires it.
I've been working in Swift,t he language itself is nice, the tooling and community documentation is a bit rough. For example Cocoapods support for Swift pods is still prerelease and there are a lot of small differences coming from Objective C that can require a little research.
I wouldn't write safety-critical code in either language though.
But, 'ready for production' is a relative term that must be considered in context. Apple is encouraging developers to submit apps with Swift, so clearly they think it's 'ready for production' in some contexts.
If you're building an app for which an obscure, swift-specific bug may cause a critical security or safety issue for your customers then perhaps go with objective-c to sleep better at night. Although my impression is that Swift is stable enough even for this category of apps.
But, I'd wager that vast majority of apps out there do not fall under that category.