The iOS technical interview: get your dream job as an iOS developer

1. The iOS technical interview: get your dream job as an iOS developer Juan Catalan jcatalan007@gmail.com

2. About me • Senior iOS developer working at Actsoft, Inc, in sunny Tampa, FL, USA • Started iOS development in 2009 • 20+ apps in the App Store • Objective C veteran, Swift enthusiast

3. Agenda • Industry requirements for a professional iOS developer • Applying for an iOS developer job • The iOS technical interview • Sample questions, advice • Reference material

4. Industry requirements for a professional iOS developer Junior • Have at least one app in the App Store (sample projects count) or a Github repository with sample code • No experience in the job needed • Know the basics of iOS development • Swift knowledge, maybe willing to learn Objective C

5. Industry requirements for a professional iOS developer Mid level • Have at least one app in the App Store which is not a sample project • 2+ years of experience • Know how to build an app from scratch and publish to the App Store • Objective C and Swift knowledge

6. Industry requirements for a professional iOS developer Senior • Have several apps in the App Store (5+) • 5+ years of experience as an iOS developer / 10+ in Software Development • Deep knowledge of Objective C and Swift and how to interface between them • Knowledge of complex subjects like memory management, concurrency, git, unit tests, automated builds, continuous integration

7. Applying for an iOS developer job • Have an updated LinkedIn proﬁle with links to your apps or have a portfolio website • Have an updated resume in word and pdf format • Have apps or code written by yourself available in Github/Bitbucket/Gitlab • Apply and prepare yourself for the interviews

8. Applying for an iOS developer job Recruiter / HR person (Technical) screening interview Technical interview / On-site interview Team interview / On-site Recruiter / HR person

9. Applying for an iOS developer job Recruiter / HR person (Technical) screening interview Technical interview / On-site interview Team interview / On-site Recruiter / HR person • LinkedIn proﬁle / resume • Match resume with the required experience • Behavior, behavior, behavior!

10. Applying for an iOS developer job Recruiter / HR person (Technical) screening interview Technical interview / On-site interview Team interview / On-site Recruiter / HR person • Match resume with the required experience • Technical questions tailored to the required experience and company needs • Could include real coding exercise to be submitted after the interview

11. Applying for an iOS developer job Recruiter / HR person (Technical) screening interview Technical interview / On-site interview Team interview / On-site Recruiter / HR person • Techical questions • General software development questions • Speciﬁc iOS development questions • Whiteboard/paper coding exercises • Real coding exercise / app

12. Applying for an iOS developer job Recruiter / HR person (Technical) screening interview Technical interview / On-site interview Team interview / On-site Recruiter / HR person • Resume questions • Techical questions • Behavioral questions

13. Applying for an iOS developer job Recruiter / HR person (Technical) screening interview Technical interview / On-site interview Team interview / On-site Recruiter / HR person • Company decision • Offer negotiation • Offer letter

14. The iOS technical interview Algorithms and data structures Design patterns Tools (Xcode, Instruments, git, …) Frameworks (iOS SDK, 3rd party libraries) Programming Languages (Objective C, Swift)

15. Objective C • Classes, instance variables, properties, methods, method signatures • Memory management: ARC/MRC, retain cycles, strong, weak, assign, initializers (designated, convenience), dealloc • Protocols, Categories, Blocks • Control ﬂow: loops (for, for-in, while, do-while), fast enumeration, switch, if-else, continue, break, return • NSString, NSArray, NSDictionary, NSSet (and mutable counterparts), NSNumber, NSDate, NSNull vs nil, NSURLSession, NSJSONSerialization, NSError • Interfacing with Swift and C/C++

16. Swift • Structs, classes, (value types vs reference types), methods, method signatures, properties, enums (with associated values), tuples, extensions, protocols, closures, generics, map-ﬁlter-reduce • Memory management: ARC, retain cycles, strong, weak, unowned, initializers (designated, convenience), deinit • Optional types (regular, implicit, unwrapping, optional chaining, default values), variables and constants, if-let, guard • Dictionary, Array, Set, String, Int, Double, Date, URLSession, URL • Control Flow: loops (for-in, while, repeat-while), switch, error handling (do - catch, throw, throws), continue, break, return • Bridging headers, interfacing Swift-Objective C, API Design Guidelines

17. iOS SDK • Support multiple versions of iOS • Foundation, Swift Standard Library • UIKit, Core Location, Core Animation, Core Graphics, MapKit • Core Data, UserDefaults, Property Lists, FileManager, SQLite • URL, URLSession, JSONSerialization • Grand Central Dispatch, Operation, OperationQueue • XCTest

18. iOS SDK: UIKit • Storyboards, nib ﬁles, segues, auto-layout vs UI in code • UIViewController, UINavigationController (and stack of VC) • UITableView, UITableViewController, UITableViewCell (custom cells), asynchronous data loading (background thread) • UIView subclass, gesture recognizers, core graphics, core animation, UICollectionView, UIStackView • UIButton, UILabel, UIImageView, UITextField, UITextView, UIScrollView, UISwitch, Segmented Control

19. 3rd Party Libraries • Knowing how to discover and install 3rd party libraries: Cocoapods/Github • Networking: AFNetworking, AlamoFire • JSON: Mantle, SwiftyJSON • Alternatives to Core Data: SQLite, Realm

20. Development Tools • Xcode: project, targets, info.plist, source control, editor (refactoring, code folding, re-indent), archive, devices, organizer, debugger (breakpoints, inspect variables, single-step) • Instruments: allocations, zombies, leaks, network, time proﬁler, activity monitor • Apple Developer Account, iTunes Connect, Beta app distribution and crash reports (TestFlight, Fabric, HockeyApp) • Git, GitHub/Bitbucket/GitLab: commit, merge, rebase, reset, stage, pull, push, fetch, fork, clone, pull requests, GitFlow branching model • Cocoapods, Carthage, Swift Package Manager

21. Design Patterns • Object Oriented Design: inheritance, polimorﬁsm, composition • MVC, Delegation, KVO, Factory, KVC, Singleton, target-action (IBOutlet/IBAction), Notiﬁcations • Protocol Oriented Design (Swift) • MVVM, Inversion of Control, Dependency Injection • General patterns: Decorator, Façade, Adapter, etc.

22. Algorithms & Data Structures • Big-O Notation • Array, string, linked list, stack, queue, binary tree, graph, hash tables • Recursion, bread first search, depth first search, binary search, merge sort, quick sort, data structure operations (insert, delete, find, traversing graphs, etc.) • Multitasking: thread, process, lock, critical section

23. Coding exercise: sample app

24. NASA Images

25. NASA Images

26. NASA Images • Downloads pictures from the Astronomy Picture of the Day website (https://apod.nasa.gov) and shows the pictures in a scrolling table view. • Uses NASA Open API web services • Uses best practices: parallel downloads, smooth UI scrolling while downloads are in progress, provides a mechanism to refresh the UI, etc. Networking JSON Image Downloader

27. NASA Images UITableView UILabel UIImageViewUIRefreshControl UITextView Progress Indicator

28. Sample interview questions

29. Sample interview questions 1. What was the latest version of iOS you worked with? what do you like about it and why? 2. Have you worked with Swift? What do you like about it? What you don’t like? 3. How memory management is handled on iOS? 4. What do you know about singletons? Where would you use one and where you wouldn’t? 5. Could you explain what is the difference between Delegate and KVO? https://www.linkedin.com/pulse/ios-interview-questions-senior-developers-alex-bush

30. Sample interview questions 6. How do you usually persist data on iOS? 7. How do you typically do networking? 8. How do you serialize data on iOS (JSON from the web or local app data to Core Data and other storages) ? 9. What design patterns do you know and use on iOS? 10.What is Auto-layout? https://www.linkedin.com/pulse/ios-interview-questions-senior-developers-alex-bush

31. Sample interview questions 11.How do you handle async tasks? 12.How do you manage dependencies? 13.How do you debug and proﬁle things on iOS? 14.Do you code review? 15.Do you test your code? What do you do to make your code testable? https://www.linkedin.com/pulse/ios-interview-questions-senior-developers-alex-bush

32. Advice • Don’t waste your bullets • Be honest • Be precise • Be respectful, be friendly, not arrogant • Never give up with though questions

33. Reference material • https://www.glassdoor.com/Interview/ios- developer-interview-questions-SRCH_KO0,13.htm • https://www.linkedin.com/pulse/ios-interview- questions-senior-developers-alex-bush • Cracking the Coding Interview: 189 Programming Questions and Solutions, Gayle Laakmann McDowell • https://careercup.com

34. Thanks! • Slides https://www.slideshare.net/jcatalan007/the-ios- technical-interview-get-your-dream-job-as-an- ios-developer

The iOS technical interview: get your dream job as an iOS developer

Esté a ler uma amostra.

Confira estes a seguir

The iOS technical interview: get your dream job as an iOS developer

Mais Conteúdo rRelacionado

Semelhante a The iOS technical interview: get your dream job as an iOS developer (20)

Mais recentes (20)