Performance & Optimization Interview Questions

Key optimization strategies include: 1) Using value types for better copy semantics, 2) Implementing copy-on-write for large value types, 3) Avoiding unnecessary object creation, 4) Optimizing collection operations, 5) Using lazy properties for expensive computations, 6) Implementing proper memory management, 7) Utilizing compiler optimizations, 8) Profiling and measuring performance metrics.

ARC performance considerations include: 1) Minimizing strong reference cycles, 2) Using weak and unowned references appropriately, 3) Implementing proper object lifecycle management, 4) Optimizing closure capture lists, 5) Managing collection strong references, 6) Understanding retain/release overhead, 7) Proper deinitialization handling, 8) Memory graph optimization.

Collection optimization includes: 1) Choosing appropriate collection types, 2) Reserving capacity upfront, 3) Using lazy collections for large datasets, 4) Implementing efficient sorting algorithms, 5) Optimizing iteration patterns, 6) Using contiguous arrays when possible, 7) Managing memory allocation, 8) Implementing custom collection types when needed.

Memory optimization techniques: 1) Using value types appropriately, 2) Implementing proper caching strategies, 3) Managing object lifecycles, 4) Optimizing image memory usage, 5) Using autorelease pools when needed, 6) Implementing memory warnings handling, 7) Proper resource cleanup, 8) Memory footprint monitoring.

Compile time optimization includes: 1) Reducing use of generics when unnecessary, 2) Optimizing complex type inference, 3) Managing module dependencies, 4) Using whole module optimization, 5) Implementing proper access control, 6) Reducing preprocessor directive usage, 7) Optimizing build settings, 8) Managing source file organization.

Network optimization includes: 1) Implementing proper caching strategies, 2) Using URLSession configuration optimization, 3) Managing request batching, 4) Implementing proper error handling, 5) Optimizing data serialization, 6) Managing background tasks, 7) Implementing request prioritization, 8) Network reachability handling.

UI performance optimization: 1) Implementing view reuse, 2) Optimizing layout calculations, 3) Managing main thread operations, 4) Implementing proper layer optimization, 5) Using drawRect efficiently, 6) Managing image loading and caching, 7) Implementing scrolling optimization, 8) Reducing view hierarchy complexity.

String optimization includes: 1) Using string interpolation efficiently, 2) Managing string concatenation, 3) Implementing proper unicode handling, 4) Using string indexes properly, 5) Managing string storage, 6) Optimizing string comparison, 7) Using string subranges efficiently, 8) Implementing proper string caching.

Protocol optimization techniques: 1) Using protocol composition efficiently, 2) Managing protocol inheritance hierarchy, 3) Implementing static dispatch when possible, 4) Optimizing protocol witness tables, 5) Using associated types properly, 6) Managing protocol conformance, 7) Implementing protocol extensions efficiently, 8) Understanding protocol overhead.

Data persistence optimization: 1) Choosing appropriate storage solution, 2) Implementing efficient serialization, 3) Managing batch operations, 4) Optimizing query performance, 5) Implementing proper caching, 6) Managing data migration, 7) Optimizing data models, 8) Implementing proper error handling.

Algorithm optimization includes: 1) Choosing appropriate data structures, 2) Implementing efficient sorting methods, 3) Managing time complexity, 4) Optimizing space usage, 5) Using dynamic programming when applicable, 6) Implementing proper memoization, 7) Managing recursive algorithms, 8) Understanding Big O notation.

Image optimization techniques: 1) Implementing proper image caching, 2) Managing image compression, 3) Using appropriate image formats, 4) Optimizing image loading, 5) Managing memory usage, 6) Implementing lazy loading, 7) Using image resizing efficiently, 8) Managing image metadata.

Closure optimization includes: 1) Managing capture lists efficiently, 2) Understanding closure overhead, 3) Implementing proper memory management, 4) Using @escaping appropriately, 5) Optimizing closure syntax, 6) Managing closure context, 7) Understanding closure lifetime, 8) Implementing proper retain cycles prevention.

Concurrent operation optimization: 1) Using appropriate dispatch queues, 2) Managing thread safety, 3) Implementing proper synchronization, 4) Optimizing task scheduling, 5) Managing resource contention, 6) Implementing proper cancellation, 7) Using operation dependencies, 8) Managing queue priorities.

Binary size optimization: 1) Managing dependency inclusion, 2) Using proper optimization flags, 3) Implementing dead code elimination, 4) Managing asset optimization, 5) Using proper linking options, 6) Managing framework integration, 7) Implementing proper code stripping, 8) Understanding symbol table optimization.