The focus of "code review" is shifting from line-by-line checks to validating an AI's initial architectural plan. After plan approval, AI agents like OpenAI's Codex can effectively review their own generated code, a capability they have been explicitly trained for, making human code review obsolete.

As AI agents handle the mechanics of code generation, the primary role of a developer is elevated. The new bottlenecks are not typing speed or syntax, but higher-level cognitive tasks: deciding what to build, designing system architecture, and curating the AI's work.

AI tools are automating code generation, reducing the time developers spend writing it. Consequently, the primary skill shifts to carefully reviewing and verifying the AI-generated code for correctness and security. This means a developer's time is now spent more on review and architecture than on implementation.

A surprising side effect of using AI at OpenAI is improved code review quality. Engineers now use AI to write pull request summaries, which are consistently more thorough and better at explaining the 'what' and 'why' of a change. This improved context helps human reviewers get up to speed faster.

With AI generating 1,300 pull requests weekly at Stripe, the critical path is shifting. When coding becomes a commodity, the bottleneck moves to human review and validation. Engineering teams must refocus from pure creation to oversight and quality assurance at scale.

As AI writes most of the code, the highest-leverage human activity will shift from reviewing pull requests to reviewing the AI's research and implementation plans. Collaborating on the plan provides a narrative journey of the upcoming changes, allowing for high-level course correction before hundreds of lines of bad code are ever generated.

AI excels at generating code, making that task a commodity. The new high-value work for engineers is "verification”—ensuring the AI's output is not just bug-free, but also valuable to customers, aligned with business goals, and strategically sound.

With AI agents autonomously generating pull requests, the primary constraint in software development is no longer writing code but the human capacity to review it. Companies like Block are seeing PRs per engineer increase massively, creating a new challenge for engineering managers to solve.

It's infeasible for humans to manually review thousands of lines of AI-generated code. The abstraction of review is moving up the stack. Instead of checking syntax, developers will validate high-level plans, two-sentence summaries, and behavioral outcomes in a testing environment.