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I released my first iOS app in 2008, the year that iPhone changed the world.

Recently, in time for World Cup 2018, I release v3 of the same app.

As I rewrite the app – from Objective-C to Swift – it dawned on me how much things have changed.

How much the tools have improved. How different designs and architectures are. How much my code has evolved.

As I look at the code evolving from v1 -> v2 -> v3 (thanks source control), I feel like I am reading my diary. It tells my story in iOS development.

v1 (2008)

• SVN Source Control (git not popular back then)
• AppDelegate is 1,600+ lines long!
• Code form is inconsistent
  • Multiple line breaks
• Commented out many code for some reason
• Table view cell are constructed with nibs, then configured with viewWithTag
• Models are dictionaries and arrays
• 1 month to finish

v2 (2014)

• iOS 6 is a big change with cleaner interface
• Wrote better abstraction
  • Replace Type1ViewController, Type2ViewController, … etc with OddsViewController, which configure the cell according to the type
• Still Objective-C (no Swift yet)
• Use of Cocoapods libraries
• Use of my own private library
• Storyboard
• Helpful models, but with lots of mutation func

v3 (2018)

• Objective-C to Swift
  • Strongly typed language eliminates many meaningless crashes.
• Better namings of everything
  • Xcode can finally can refactor by renaming methods and types
• Scalable UI
  • Auto Layout for any device size or orientation
  • Dynamic (Font) Type
• No more storyboard
  • All UI created by code with constraints
• Better Architecture
  • Clearer responsibilities
  • Reasonable dependencies
  • MVVM with RxSwift
• Unit Tests with API fixtures
• Fastlane for managing certs, provisioning profiles, building and uploading releases
• 7 days to rewrite