Daily coverage of Apple’s WWDC 2019 conference, by John Sundell.

A Swift by Sundell spin-off.

7 essential WWDC session videos for iOS developers

There’s been such an incredible amount of quality content from Apple this year — both in terms of announcements, new developer tools, updates to existing APIs, and of course — sessions.

While I’m still working my way through all of the 84 (!) videos that Apple have released so far (not including Friday’s sessions), I wanted to share an initial set of seven videos that I think are essential for any iOS developer to watch.

I say “iOS developer”, because that’s my personal, primary context. While I do a lot of other kinds of development as well these days, and I aim to watch every single WWDC session video over the course of the next months, the iOS-focused ones are the ons I’ve prioritized so far.

So, without further ado, here goes — seven essential WWDC videos for iOS developers to watch — in no particular order, and not counting the keynote and Platforms State of the Union.

What’s New in Swift

If you haven’t been closely following Swift Evolution lately, then this session provides a great introduction to some of the new features introduced in Swift 5.0 and 5.1. Since SwiftUI relies heavily on some of these new features, it’s a great session to catch up on before diving into Apple’s new declarative UI framework.

Introducing SwiftUI: Building Your First App

I think this video is almost impossible to skip. While adopting SwiftUI is not necessarily something you might want to do right away — it’s clearly the direction that Apple aims to take UI development for their platforms going forward — so learning at least its fundamentals is an investment that’s more or less guaranteed to pay off.

Advances in UI Data Sources

An excellent, thorough, and well-paced walkthrough of the new diffable data sources APIs introduced as part of this year’s SDKs. I’m already in love with these new APIs and how much they modernize, and simplify, some of the most fundamental parts of UIKit — UITableView and UICollectionView. This session is a must-watch for anyone building apps for iOS.

Implementing Dark Mode on iOS

I personally think Dark Mode on iOS looks fantastic, but more importantly — as soon as you build your app using the iOS 13 SDK, you’ll need to support it. This session gives you an introduction to Dark Mode, the principles behind it, and tips on how to add support for it in an app — including things like color management, using the new vibrancy materials, and managing layers of content when in Dark Mode.

Combine in Practice

Combine is Apple’s new reactive data framework, that’ll come very much in handy when building declarative UIs using SwiftUI. This session will give you a great introduction to that framework, and reactive programming concepts in general, by contextualizing Combine’s APIs and concepts using practical code examples and demos.

Modern Swift API Design

Regular Swift by Sundell readers will know that I often use the phrase ”Everyone is an API designer” — meaning that API design is not only for framework authors, it’s for all of us. In another stellar talk by Ben Cohen, you get to learn about the principles that Apple themselves used when designing some of their latest APIs — including SwiftUI and RealityKit.

Modernizing Your UI for iOS 13

Every edition of WWDC has some form of session designed to help developers adopt the essential new APIs that provide customization options for some of iOS’s new visual styles — and this session is this year’s version. This talk also starts with some important new rules for apps around adopting modern OS-level UI features, that’ll take effect in April of next year.

That’s it — those are my seven most recommended videos for iOS developers so far. There’s of course a ton of other amazing session videos to watch — on topics ranging from Augmented Reality, to Machine Learning, to Metal, to Xcode tips and tricks, and beyond — all of which are available on Apple’s developer website. Here are links to lists containing all of the sessions from each day, grouped by topic:

This will be my last article covering Apple’s amazing WWDC 2019 conference. It’s been an amazing experience writing about some of the exciting new tools and APIs that Apple announced this week, and although I haven’t been able to cover nearly everything — I hope you’ve enjoyed all the articles, podcast episodes and interviews that I’ve published during the week.

If you’re not yet subscribed to Swift by Sundell, then make sure to check that out to keep following along with my weekly articles and bi-weekly podcast episodes. Next week, I’ll also be posting a complete technical retrospective on how I built and ran this site, so stay tuned for that.

Until then, one last time, thanks for reading! 🚀