Everything in The Nest tagged AI Agents.
Ask an agent for a login flow and you tend to get a ?next= parameter redirected to whatever it contains. It is the obvious implementation, it is an open redirect, and the remedy was documented years before the model was trained.
An AI agent that ran certbot once did the work correctly and made no commitment about the renewal. The setup is in your repository; the recurring obligation it created is in nobody's calendar.
Four agents changing one codebase means four diffs nobody has time to read end to end. The answer is not fewer agents: it is checking the deployed site, which costs the same however many changes arrived.
Generated markup is verbose, imports whole libraries for one function, and inlines assets because that works. Every test still passes. The cost lands on a phone on a slow connection, months later, as a number with no cause attached.
A strict Content-Security-Policy is usually the thing standing between an agent and the feature it was asked to add. Widening it is the path of least resistance, it is never mentioned in the summary, and nothing about the site looks different afterwards.
A canonical tag pointing at staging, a noindex that shipped, a test API key in production. Each is invisible on a developer's machine and expensive live, and copying config between environments is the fastest way to make something work.
The instinct is to add monitoring once a site has traffic worth protecting. That gets it backwards: an empty site is the one failure mode nobody reports, because your first hundred visitors leave instead.
One agent edits the backend, another edits the frontend, a field quietly changes type, and every build stays green. The screen renders blank where a number belongs, and only something watching the deployed endpoint will tell you.
Ask an agent to add analytics and it adds a tag. Do that four times over six months and your page is executing code from hosts no one on the team chose, on your origin, with your users' data.
Between a visitor typing your name and a request reaching your server sits a system you did not write and cannot review: a registration, a delegation, a zone, and a chain of caches. Here is how each of them fails.
Given a red signal, an agent optimises for the signal. That is not a flaw in any particular tool — it is what optimisation means, and it changes which signals are worth having.
An AI agent can produce a working-looking site faster than any human can review it. The defects live in the gap between the agent saying it is done and a stranger being able to use it.