I measure adherence to preestablished acceptance criteria, the same as I've done before while either coding myself or managing other engineers.
It sucks, but you don't usually have the time to pour over code when you manage multiple engineers either, so you have to learn how to do thorough but targeted reviews, minimize distraction, maximize efficiency, etc. A lot of these skills transfer over to managing agents.
We've only had truly decent agents capable of running long-horizon tasks for less than a year, I think it's worth calibrating around that: it's too soon to expect the entire industry to visibly shift.
That said, every senior engineer I know has gone all-in on agentic development, and juniors I mentor are getting a lot done as well.
With juniors it's important to make them understand that these models can't be blindly trusted and the output needs to constantly be critically evaluated.
But engineers who know exactly what they are doing have really been able to make some awesome things this year. I'm also working on a few really cool things, more than before, more ambitious as well, without sacrificing quality or craftsmanship.
I can also seem where some trends are headed. The breadth of software available to both harm and help you is going to explode, and computing is going to look a lot different soon. I'm already building targeted health apps for myself, bespoke personal apps and tooling, development tools, I'm working on games, libraries, various kinds of research, you name it. It feels like an intellectual Renaissance, and within a decade I expect things to look a lot different even if models stopped improving today.
You do have to work differently with these models. Your code evolves in a different way, and testing habits have to adapt. Clients are going to accept less stable but more ambitious demos. Prototyping and research have suddenly become very cheap. We're going to see the effects of the spread through STEM and the arts.