Introduction

There are so many buzzwords and best practices out there, but let’s focus on something more fundamental. What matters is the amount of confusion developers feel when going through the code.

Confusion costs time and money. Confusion is caused by high cognitive load. It’s not some fancy abstract concept, but rather a fundamental human constraint.

Since we spend far more time reading and understanding code than writing it, we should constantly ask ourselves whether we are embedding excessive cognitive load into our code.

Cognitive load

Cognitive load is how much a developer needs to think in order to complete a task.

When reading code, you put things like values of variables, control flow logic and call sequences into your head. The average person can hold roughly four such chunks in working memory. Once the cognitive load reaches this threshold, it becomes much harder to understand things.