Hi, I‘m Aleksandar Vacić

I spent 15 years in web development, working from simple personal web pages up to enterprise-level sites. This blog has my web posts dating back to 2003. I lost interest in web around ‘08 and was happy that iPhone appeared at the time to kickstart the Age of Mobile development.

In early 2012 I went full-time with iOS development through Radiant Tap after it was clear that iOS dev is perfect blend of my passions: user experience and efficiently crafted code.

Since then, almost all of the posts are iOS, Objective-C and – since autumn ‘16 – Swift related.

Latest posts

Implement data detectors inside UILabel

How to recognize links and other stuff (normally available only on UITextView) and make them interact-able.

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Using NSFetchedResultsController’s diffable snapshot with UICollectionView’s diffable data source

A look into the intricate details of Core Data NSFetchedResultsController’s new delegate method to work with diffable data sources driving a collection view.

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Bitmask (bitwise) values in Core Data

Swift’s OptionSet is great type. Here’s how you save and read such values in Core Data.

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My work

I have created over 70 apps on the App Store, for myself and various clients under Radiant Tap marquee, which has since grown into proper agency.

We offer teaching and training as well as contract work under Standard and Enterprise programs. If you are interested — contact us today.


Former co-organizer of the iOS Developers Srbija Meetup group and frequent speaker at our (rather) infrequent meetups.

I value and respect open source and contribute to the body of available code as much as I can.


Slides for all my talks are always available on SpeakerDeck. Last few notable appearances…

SwiftUI for UIKit developers
at PragmaConf, Bologna IT,
(video, slides, transcript in English)

Onion-like iOS app architecture
at App Builders, Lugano CH,
(slides and video in English)

Highly maintainable App Architecture
at NSSpain, Logroño Spain,
(slides and transcript in English)

Fresh Cup of iOS 10
at VoxxedDays Belgrade,
(slides in English, video in English)

Where to Focus to Grow your iOS app
at Mobile Growth Meetup,
(slides in English)

Keynote worthy Apple Watch apps
at VoxxedDays Belgrade,
(slides in English, video in English)