iOS Knowledge Matrix

User Interface

Qualified	Competent	Expert
Autolayout
Anatomy of constraint, external and internal changes, autolayout vs frame-based layout	Stackview, debugging autolayout, anchors, safe area, self-sized views, Hugging priority/Content compression resistance"	Layout directions (left-to-right/right-to-left), VFL, autoresizing masks (springs&struts)
Xibs (Nibs), Storyboards
xibs and/vs storyboards, custom UI elements in xibs and storyboards, file's owner, loading from xibs and storyboards programmaticaly, segue, pass data via segue, customization ui best practices	IBInspectable, IBDesignable, size classes, xib vs nib, NIB object lifecycle, unwind segues, git conflicts in xibs and storyboards, xib's xml structure
Animations
animations via autolayout, UIView.animate, CALayer, CAAnimation	facebook pop, UIDynamics, 3D animations, UIViewPropertyAnimator, CADisplayLink	SpriteKit? Adobe After Effects?
Other
Localizations HIG	Internationalization i18n & Localisation l10n

Data persistence

Qualified	Competent	Expert
Core Data
Core Data Stack & Architecture, Relationships, Data Types, fetching	Pefrormance, concurrency, multithreading, multiple contexts, changes and updates tracking	Migrations, nestedcontexts, profiling, persistence under the hood (SQLite, XML, Binary, In-memory). iCloud synchronization,Security
Other approaches
UserDefaults, KeyedArchiver	Realm, Keychain

Languages

Qualified	Competent	Expert
Swift
Basic syntax, optionals, control flow, error handling, memory management (ARC), classes, structures, enums, functions, initialization/deinitialization, inheritance	Objective-CInteroperability, POP, generics, type safety, KVO/KVC, value and reference types, subscripts, bitwise operators, overflow operators, operator methods, access control	Swift performance, Swift + LLVM, method dispatch, swizzling, @dynamic, final, playgrounds, Swift Standard Library
Objective-C
Basic syntax, variables and types, collections, initializations	Blocks, categories, Integrating Swift into objc, C/C++ code usage inside Obj-C	Runtime, Class structure (isa), Method swizzling, MRC

Networking

Qualified	Competent	Expert
URLSession
NSURLSession basics, encoding/decoding of URL data, lifecycle of a URL Session	Multipart requests, response caching, handling redirects	Background handling, NSURLAuthentication, TLS Chain Validation, streams, sockets, NSURLConnection
Response handling
JSONSerialization, error handling	Codable/Decodable, NSCoding
Building a network layer
Alamofire, mappers	Moya , CFNetwork

Deployment

Qualified	Competent	Expert
Understanding of code signing, provisioning profiles, app schemes configuration. Launching app on device	Working with iTunes Connect, App Review Guidelines. Build automation, beta-testing tools and deployment platforms. Fastlane	Advanced automation skills (plugins, scripts)

iOS essentials

Qualified	Competent	Expert
UIViewController lifecycle, iOS app lifecycle, NotificationCenter	Working with filesystem, background modes, xcode project structure

Multithreading

Qualified	Competent	Expert
Grand Central Dispatch
basic knowledge about multithreading and concurrent programming, deadlocks, race conditions. async vs sync, main vs background	Dispatch queues, units of work, prioritizing, quality of service, timing (time & after)	Dispatch groups, semaphores, dispatch I/O, dispatch sources. Interprocess communication, XPC Services
NSOperation
basic knowledge about multithreading and concurrent programming, deadlocks, race conditions.	Operation executing, cancelling and configuring. Operation states. NSOperationQueue. Subclassing and overriding. BlockOperation	Operation dependencies, NSOperationQueue
Thread (NSThread)
	Ability to work with Thread. Initializing, starting/stopping, state handling, prioritizing. Locks, NSRunLoop.

Marketing

Qualified	Competent	Expert
Push Notifications, URL schemes	Deep linking, Universal links, App Indexing	Advertisements (AdSupport, AdMob etc)

Testing

Qualified	Competent	Expert
Basic knowledge of unit tests	Complex unit tests, XCTest, Quick/Nimble (Kiwi for Obj-C)	TDD, UI tests, web testing and debugging

Xcode build system

Qualified	Competent	Expert
xcodebuild, xcrun. Targets, bundles, frameworks, libraries. pbxproj, xcconfig, xcodeproj, xcworkspace, xcscheme, xctoolchain. Build phases, shell scripts, build rules, build configurations.	lldb, lipo, llbuild, swift package manager, linker. Flags

Security

Qualified	Competent	Expert
Keychain, iOS security guidelines, TouchID, FaceID	Security framework - authorization and authentication, code signing, cryptography, result codes. Secure coding guide. iOS security overview

Performance

Qualified	Competent	Expert
Basic knowledge of measuring app performance with Xcode instruments. Object Graph, Network Link Conditioner. UI optimization (opaque views, fat XIBs, image sizes, main thread blockers, layers vs paths etc)	Optimization modes in Xcode, whole module optimization, gzip compression, lazy load and reuse of views, caching, tableview and collectionview optimization, date formatters	Memory warnings handling, speeding up app launch time (static vs dynamic libraries, merging several frameworks into one monolithic)

Architecture Patterns

Qualified	Competent	Expert
Delegate, MVC, observer, chain of responsibility, Singleton.	MVP, MVVM, VIPER, VIP, Router. State, Strategy, Visitor. Abstract Factory, Factory Method, Builder. Adapter, Decorator, Facade.	Flux, Redux. Mediator, Memento, Command, Prototype, Proxy

Functional/Reactive programming

Qualified	Competent	Expert
Basic knowledge. Recursion	RxSwift/ReactiveCocoa/ReactiveSwift/ReactiveKit, higher order functions.	Futures&Promises. Pure functions. Complete understanding of reactive approach. Functors, Applicatives and Monads.

Hardware & Media

Qualified	Competent	Expert
Basic AVFoundation, CoreBluetooth, AVKit	Core Audio. Advanced AVFoundation, CoreBluetooth, AVKit. WebKit. Core Telephony, Core Media	Core Motion, IOKit, Compression

Other

Qualified	Competent	Expert
Basic MapKit & CoreLocation. Basic socials integration. Sharing	AddressBook, AddressBookUI, Messages, MessagesUI, Advanced MapKit & CoreLocation. Advanced socials integration.	In-app purchases

Optionals

Qualified	Competent	Expert
App extensions	tvOS, watchOS, SpriteKit, SceneKit, HomeKit, HealthKit, EventKit	Metal, CoreGraphics, OpenGL, cross-platform development, ARKit CryptoTokenKit, SiriKit