testing

This article argues for the value of example code for software projects. The primary audience are software engineers working on libraries and open-source code. Executable example code is probably the most valuable artifact one can add to projects ranging from single-purpose libraries to larger frameworks. This applies from the API design phase of a library to maintaining them in the long term. The repositories of the Android libraries that I maintain(ed) typically include dedicated sample apps....

This article describes how to add a CLI module to an existing Android Studio project that generates an executable .jar archive. The primary audience are software engineers working on Android. When developing for Android – or other mobile platforms – the change-to-effect latency can be often quite high due to the involved compilation and cross-device communication. The regular unit tests get around this by executing in a VM on the host machine....

This article explains an often-overlooked effect that can distort metrics during feature roll-out. The primary audience are software engineers and managers working on infrastructure and libraries. I want to motivate this problem with a fictive scenario: Alex wrote a replacement for an old and inefficient component in their app. It took the team a few weeks to implement and they carefully measured on test devices that it improves all core metrics....

This article explains advanced A/B test concepts. The primary audience are engineers encountering such A/B tests for the first time. A/B tests allow engineers to validate fixes, test for regressions, and measure improvements. In most situations the standard approach is to create a control and a test group of equal size (e.g. both 5%). Users within the test population (e.g. 10%) are then randomly assigned to one of these. However, sometimes more intricate methods can improve the user experience and make deployment safer and more effective....