Decodering: Effective AI Assisted Coding

Effective AI Assisted Coding

I started my journey into AI-assisted software development a few years ago, essentially for fun. It was pretty difficult to get trustworthy results, even after a year of daily use of GitHub Copilot. For professional-level results during this period, it was necessary to keep changes very small - to the scope of a single method. This picture changed with the arrival of Claude Sonnet 4 in June 2025. Unlike its predecessors, it was able to follow detailed specifications without derailing itself.

In this Decodering, I will show the method I use for AI assisted coding in GitHub Copilot in VSCode that exploits this step-change. In the first half of the talk (30 mins), I will run through the widely shared good habits and the core of the method itself, which makes heavy use of detailed specs.

In the second half of the talk (60 mins), I will then demo writing a console application from a previously prepared specification using Claude Sonnet 4.5, demonstrating the technique. This will be reasonably authentic development, although in the interests of fitting inside the time available, I have modified the spec I originally used, adding clarifications reduce the likelihood of rework.