Another Small UIKit Debugging Adventure

Working with closed source APIs sometimes requires us to use advanced debugging techniques to track down issues that cannot be explained by our application code alone.

This week I had an interesting debugging session in which I learned more about the behavior of apps with multiple UIWindows. These kind of posts are mostly useful for me as an attempt to retain some knowledge. But I hope this story is entertaining and useful to you too!


Bridging Swift Types to Objective-C

At PlanGrid we started adopting Swift prior to the 1.0 release. Despite the tooling problems you’re probably familiar with, we’re still excited Swift users and have written almost all new code since the summer of 2014 in Swift. We are doing that within a large legacy codebase so more than 50% of our application code is still in Objective-C. As in many projects Swift and Objective-C need to co-exist.


Why I don't Believe in Uber's Success

I wanted to write this blog post for well over half a year. I don’t believe Uber will be a successful business. I’ve been making my points in individual conversations over and over again - with this post I’m creating a writeup of my arguments that I can share in future.

Since I’ve had a lot of discussions about Uber in person, it makes the most sense to write this piece in the platonic dialogue form.


Understanding Data Race Detection by Implementing it in Swift

TL;DR: In order to learn more about how Thread Sanitizer’s data race detection works I’ve implemented a very simple version in Swift. You can find it on GitHub. We all know concurrency is hard. It’s easy to make mistakes when attempting to synchronize access to shared resources and the resulting issues are often extremely hard to reproduce and debug. So I was very excited when I learned about data race detection in LLVM’s Thread Sanitizer in this year’s WWDC Session 412. Read More...

Apple Isn't Doomed Quite Yet

The outcry in the Apple community after the latest Apple event has been huge. For many of its loyal customers it seems that the last bit of the remaining magic of the Jobs era has vanished. I personally have only been following Apple more or less closely since 2012. From this position I feel like I’m able to view the state of Apple from a mainstream consumer’s angle. From that vantage point it seems like Apple has made mistakes, but it is not doomed quite yet. Read More...

Declarative API Design in Swift

In my first real job as an iOS developer I built an XML parser and a simple layout engine - both had in common that they had a declarative interface. The parsers was driven by a .plist file that mapped XML elements to Objective-C classes. The layout engine allowed you to describe layouts in an HTML-like language (this was before AutoLayout & CollectionViews existed).

Though neither of these libraries were even close to perfect, they showed me four main advantages of declarative code:


Broken Toolchain Post Mortem

Dependency managers, IDEs, continuous integration, automated tests - all these tools are created to supercharge a developer team’s productivity. While modern development tools are amazing in many ways, they unfortunately also add maintenance burden to a project.

Ask me about migrating our Bitrise & fastlane CI workflows to Xcode 8.

The goal of this post it not to blame any individual party. I’m writing this for the following reasons:

  • share my frustration (if you’re feeling stupid for struggling with tooling, hopefully you won’t anymore after reading this)
  • keep track of the issues I encountered & fixed (always helpful, and I’ll never forget why it took 3 days to fix all CI workflows)
  • reflect on what the causes of complicated tooling are and how they might be fixed in future

I also have a somewhat special relationship to tools. I remember how, as a student, complicated tooling almost deterred me from a career in software development - “If I can’t even get a J2EE app configured and running, I probably shouldn’t be a software developer”. This post is some form of self-therapy…