Hello, World!
My name is Steffen and I'd like to welcome you to my personal website and blog! I'm a German computer science student who really enjoys coding—especially for Apple platforms.

If you like my content, consider giving my website one of your precious GitHub stars—thank you!


Essential WWDC17 Sessions

May 20, 2018 My personal top 10 picks from WWDC17 in preparation for this year's conference

It’s almost time for WWDC18 and if you’re still looking for something to watch on your flight to San Jose this year: Search no more because here are my personal top session from 2017 to (re-)watch!

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Golden Gate

May 16, 2018 Logic gate playground and my WWDC18 scholarship submission.

Just like the year before, Apple offered a WWDC ticket to students, who submitted outstanding visually interactive Swift Playgrounds.

In this post, I’d like to show what I’ve created for my submission: A logic gate simulator in the WWDC18 theme that features several puzzles as well as a sandbox and some advanced creations.

You can play around with the source code on GitHub!

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April 7, 2018 Stud.IP to Go

StudApp is an iOS application for the Stud.IP learning platform, which is used by more than half a million students and lecturers at over 40 German universities and 30 other organizations like the German Football Association or a state police.

This project aims to take this platform to the next level by leveraging native capabilities of iOS. With StudApp, it easier than ever to browse your courses, documents, and announcements! Being officially certified by Stud.IP e.V., it provides excellent ways to stay up-to-date.

And—just like Stud.IP itself—StudApp is completely open source and free to be used by anyone as an no-cost app on the App Store.

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Modern Core Data in Swift

March 8, 2018 An opinionated guide to employing Core Data in a modern Swift app.

Having been released as early as 2005 alongside with Mac OS X Tiger, Core Data has come a long way. But despite Core Data’s age, Apple has applied serious modernization efforts during the last few years while also adding many new and exciting features.

Due to these modernizations you can now use Core Data with natural and concise Swift syntax. And—using the power of Swift protocols and extensions—one can make working with Core Data even funner!

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Reachability in Swift

March 4, 2018 Reacting to network reachability changes through a clean API.

In this post, I would like to share my implementation of a simple network reachability service that provides current state and posts notifications when network conditions change—without the need for a third-party library.

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Persistent History Tracking in Core Data

February 15, 2018 A guide to accessing a shared NSPersistentStore across multiple processes.

At WWDC ‘17, Apple introduced a number of new Core Data features, one of which is Persistent History Tracking or NSPersistentHistory. But as of the time of writing, its API is still undocumented. Thus, the only real reference is the What’s New in Core Data WWDC session.

Since Persistent History Tracking makes sharing an NSPersistentStore across multiple processes and is one of my favorite new Core Data features, it is unfortunate that it mostly seems to fall of the radar.

The purpose of this post is to give a real-world example on how to use it and what makes it so great.

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February 15, 2018 Functional programming playground and my WWDC17 scholarship submission.

In 2017, Apple—once again—offered students and members of STEM organizations the opportunity to attend WWDC as part of a scholarship. In contrast to the year before, Apple set out a specific yet creative task: To create a visually interactive Swift Playground, either for Xcode or iPad.

Wanting to take this opportunity, I created my own Swift Playground Book named Reduce, which teaches basic Functional Programming concepts in a playful manner. Its main feature is visualizing array operations like filter, map, and reduce to make these concept easy to comprehend.

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Hello, World!

February 15, 2018 An introduction to my personal website.

Hey there, welcome to my website!

As this is very first post, please let me introduce myself: I’m Steffen, a German computer science student, and I love coding, especially in Swift or for Apple platforms.

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