How Code in the Age of Artificial Intelligence Becomes Write-Only and Disposable

Artificial intelligence (AI) makes all code write-only, Phillip Mortimer argued in his talk Complexity and Creativity in Software Engineering at QCon London. It’s too dense to read, and tests define the behaviour and become the documentation. Code is also disposable; it becomes easier to rewrite than to debug. Humans can’t review AI-generated code at scale. Mortimer suggested automating reviews and letting agents self-heal software via observability. Intent decouples from implementation; developers should focus on creativity.

In the age of AI, all code is write-only, Mortimer argued. He quoted Eric S Raymond:

Write-only code is code so arcane, complex, or ill-structured that it cannot be modified or even comprehended by anyone but its author, and possibly not even by him/her.

Certain languages are write-only by design, trading readability for incredible power and performance, Mortimer said. He mentioned APL and regular expressions. These languages represent a kind of complexity that comes from extreme density.

A principle to deal with such code is that the tests define the behaviour:

When you write code that is too dense to read, the only way to understand what it does is through extensive test cases. The tests become the documentation for your code.