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Hi, I’m Constantin

I am a Software Developer from Germany and enjoy building stuff and tinkering with all kinds of things. If it provides a chance for me to learn I am most likely interested.

I regularly try to challenge myself to learn new skills and try to pick them up on a budget. Investing a bit of your own money into yourself to improve your own skill-set will always give you the return of your investment, and if it’s only to help friends or family with a problem.

I used to call myself a iOS software developer, but since I haven’t done it in a while I struggle to still call myself that. I used to work for CircleCI, got into many fights with and wrote about xcodebuild and how to work around all kinds of pitfalls in Xcode when it comes to CI. If you do anything related to iOS CI and have written the words “fastlane” or “xcodebuild” into a YAML configuration file before it’s quite likely that you have read something that I wrote.
I also used to work for MacStadium helping them build a new datacenter in Frankfurt and another one in Silicon Valley. I also tried to make the iMac Pro in a 19" server rack a thing, which sadly never shipped to customers as an option…

These days I am working on Guardian Firewall and annoy my coworkers by trying to ship really efficient software that respects the users data plan but most importantly their privacy.

You can reach me online on Twitter @tzeejay or send an E-Mail to