Native iOS App Development in Objective-C
Objective-C is not legacy in the sense of "outdated and doesn't work." It's a production-ready language with full Apple SDK support that still compiles to the same binaries as Swift. The difference is that new Apple APIs are released with Swift-first annotations, and some concurrency features are unavailable. For maintaining existing Objective-C codebases or specific client requirements, it's a fully viable path.
When This Is Relevant
Main scenario: large Objective-C codebase where full migration is impractical. Adding new functionality in ObjC maintains consistency, reduces risk of errors at Swift/ObjC boundary, and simplifies code review for the team.
Second scenario: C/C++ integration. Objective-C++ (.mm files) allows direct mixing of C++ and ObjC code — valued in embedded, audio, game engines where core library is in C++. Swift calls C++ via bridging header, but it's more complex and less transparent.
Architecture and Patterns
MVC is UIKit standard, but in ObjC it tends to become Massive View Controller. We delegate logic to separate classes: NSObject descendants as service layer, NSOperation / NSOperationQueue for managed concurrency, NSNotificationCenter for loosely coupled events.
Memory management patterns: ARC covers most cases, but __weak and __unsafe_unretained require care in delegate patterns and block callbacks. retain cycle in ObjC block — self captured implicitly, needs __weak typeof(self) weakSelf = self plus __strong typeof(weakSelf) strongSelf = weakSelf inside block.
Network layer: NSURLSession with completion handlers or Alamofire (works beautifully from ObjC via bridging). JSON parsing: NSJSONSerialization natively or Mantle for model mapping.
Common ObjC Project Problems
EXC_BAD_ACCESS on nil-dereference happens less because message to nil in ObjC returns 0/nil instead of crash — but this masks logical errors. NSZombies (Edit Scheme → Diagnostics → Enable Zombie Objects) helps catch accesses to freed objects in Debug builds.
Category collision: two different pods add category to NSString with same method name — undefined behavior. Shows as random crash or unexpected behavior. Solution: namespace prefixes for category methods (my_trimmed instead of trimmed).
Xcode 15 emits warnings on ObjC code not marked NS_SWIFT_UNAVAILABLE — not errors, but worth investigating.
Process
Analogous to Swift development: Clean Architecture adapts to ObjC without loss. Unit testing via XCTest works identically. Fastlane for CI/CD — unchanged. Firebase Crashlytics, Amplitude, Segment — all connect via CocoaPods with ObjC-compatible APIs.
Timeline and cost comparable to Swift development of similar scope. Simple app: 3–4 weeks. Complex with integrations: 2–3 months. Calculated individually after ТЗ analysis.