Why AI hasn’t replaced software engineers, and won’t

Simon Willison · 2026-06-14 · 3 min read

"The real bottlenecks [are] (1) deciding and specifying what to build, (2) verifying and being accountable for what is delivered, and (3) the deep human understanding — of the codebase, the business, and the environment — required to carry out both of these." "Give me all of the AI assistance in the world and the value I produce will still be reliant on how deeply I understand both the problems and the solutions that the agents are building for them."