Insights from WWDC 2017: Xcode 9, iOS 11, CoreML, ARKit and Development Tips

Preface

Hujiang, a professional online learning platform with over 100 million registered users, sent a technical manager and the author to Silicon Valley for WWDC 2017. After three days of sessions, this piece reflects on the key take‑aways rather than repeating public reports.

Xcode

Xcode 9 brings full support for Swift, dramatically improves the Source Edit experience, and enhances Source Control by integrating GitHub management and an Open in Xcode button for one‑click project opening. The biggest highlight is wireless debugging over Wi‑Fi, provided the device runs iOS 11 and is on the same network; the first connection still requires a USB cable to enable Wi‑Fi debugging in the device manager.

Xcode 9

Debugging device must run iOS 11

Both device and Mac must be on the same Wi‑Fi network

First‑time Wi‑Fi debugging needs a USB connection to enable the option in device management.

Note that iOS 11 is still a developer preview and can be unstable (e.g., Control Center may fail, third‑party apps may crash). It is advisable to test on a spare device such as an iPad.

Swift Playground requires a developer account to request a TestFlight invitation, and it is currently limited to iPad.

What We Need to Do for iOS 11

WWDC 2017 is dubbed the "hardware year," so most focus is on new hardware. API changes are minimal; for example, developers only need to adapt to the large navigation bar title . tvOS developers should note new data‑binding views and protocol‑type improvements that boost loading performance.

iTunes Connect has been revamped to include phased releases.

Swift 4 details are omitted because they were announced before the conference.

ML, AR, VR

The sessions repeatedly mentioned Machine Learning (ML) and Augmented Reality (AR). Apple encourages ML app development by providing the CoreML framework, Xcode 9’s visual model inspector, and the open‑source coremltools Python package for converting third‑party models to Apple’s format. CoreML’s API is intentionally simple to let developers focus on training data, though it does not yet support TensorFlow models. Apple claims its image‑recognition speed surpasses Google’s. ARKit is also available, but only on iPhone 6s or later and iPad Pro.

Other Tips

Apple’s design philosophy is world‑class; developers should book a User Interface Design slot to showcase their apps to Apple designers and gather feedback. Since the presentation time is limited to 30 minutes, preparation is essential.

Prepare a pre‑recorded video because on‑site network conditions may be unstable.

Prepare concise, critical questions; avoid asking everything.

Ensure the app is localized in English to make it easier for designers to evaluate.

Conclusion

For developers, WWDC 2017 reduces the amount of adaptation work compared with previous years. Observing Apple’s direction in ML, AR/VR, and other emerging technologies suggests that leveraging the newly released APIs can inspire innovative ideas.