Live-Coding Exercises
Non-Obvious Tips for Preparation and Execution 08 May 2025
One of the most-read posts on this blog is this one about typical iOS take-home coding exercises. The post has 3,797 views at time of writing, and several readers have privately thanked me for writing it. But, in my experience, the application process for many companies involves not a take-home coding exercise but rather a live-coding exercise. The candidate typically has forty-five minutes to implement an app from scratch that is similar to the app described in the post mentioned above but without unit tests or dependency injection.
The live-coding exercise is a different beast. Much of the knowledge required for a take-home coding exercise is applicable to a live-coding exercise, but the extreme time constraint of a live-coding exercise means that success is unlikely without extreme practice, preparation, and time-saving. Worse, the competitiveness of the job market means that, even if you complete 80% of the requirements of a live-coding exercise, you will be rejected in favor of another candidate who completes 100%.
In this post, I describe practice, preparation, and execution that make success in a live-coding exercise more likely. In an accompanying YouTube video, I apply this knowledge and complete a live-coding exercise within forty-five minutes.
This post is not about preparing for and succeeding in data-structure-and-algorithm interviews. Learning materials for those interviews are available elsewhere.