Tjeerd is the author of the book "Swift in Depth", published by Manning. He’s also a consultant for Swift and iOS related projects with 17 years of programming experience. He works at ING, helping build the highly rated, highly used "Bankieren" app, but also to help ING scale up by streamlining ways of working, and writing code that’s used by multiple teams from multiple countries, and most importantly, helping others to become better developers.

When he's not programming, he's busy being a dad of two daughters, and enjoys dabbling on an acoustic guitar.