This means that individual engineers move up the stack—no longer locked up as specialists in a certain system or framework, they’re able to own the product experience more or less end-to-end, even across multiple platforms. Productivity has accelerated so much that the bottleneck is no longer engineering, but rather the hard strategic questions about what to build next.

With Codex, “engineers get to spend a lot less time thinking about exactly how they build, and more time thinking about the outcome,” Dolphin explains. That outcome might take the form of screenshots or video that the agent can build towards, a certain performance or test result, or a brand new feature idea.

Nextdoor recently released Opportunity Alerts, which let people find service providers near them; with Codex, engineers are driving the product experience and roadmap. As an example, one engineer working on the alerts realized it would be helpful to show service providers on a map. Historically, that kind of feature would have required collaboration between three teams—mobile, frontend, and backend engineering—and might have never made it out of the backlog.

But with Codex, “we were able to have one engineer build it end to end,” Dolphin explains, “which means not only are they able to drive the product faster, but they’re able to better understand the actual product experience and what the right thing to ship is.”