AWS re:Invent 2025

Most of What They Automated Still Goes to a Human

原演讲者: Eric Brandwine, Vice President and Distinguished Engineer, Security · Amazon

来源已核验演讲日期待核实session58:04EN4 分钟阅读

What separates an automated security workflow from one that still needs an engineer is not model capability but whether anything other than a person can verify the result.

The most honest slide in this session is near the end. Most of the security processes they have automated still route their output to security engineers rather than to the business, because the results are not good enough (51:35).

That sits about thirty minutes after a story about two engineers building something in two days that runs a training exercise in seven minutes for ninety-one cents (17:16, 17:45). Both are true, and the gap between them is what the session is actually about.

What separates the two outcomes

The distinguishing factor is not model capability. It is whether the task has a verification loop that a machine can close.

The prototype worked because the exercise had a known answer — a training scenario, run to completion, checked against expectations. The processes still routed to human engineers are the ones where correctness is a judgement call, and no amount of throughput helps if a person has to evaluate every result anyway.

That reframes the automation question. The useful thing to ask about a workflow is not whether a model can do it. It is whether anything other than a human can tell that it did it correctly — and the answer to the second question determines whether the first one matters.

The verification techniques they actually use

Three specific loops appear, and they are the transferable part of the talk.

The first is citation. Rather than trusting an answer, require the model to produce sources, then click through and check them (32:28). The reduction in effort is real and partial: you still verify, but you verify against a pointer rather than searching for one.

The second is having the model check its own output, which costs more in tokens and saves time (33:22) — described plainly as a trade the speaker is happy to make. The framing is right. This is not a claim that self-checking makes output correct; it is an observation that tokens are cheaper than attention.

The third is the strongest, because it is not probabilistic at all. A loop that compiles the generated code guarantees the result is syntactically valid and contains no invented library calls (35:38). The model proposes, the compiler disposes, and no judgement is involved.

Ranking those by how much trust they actually transfer: the compiler loop is verification, self-checking is triage, and citations are a way of making human verification cheap. Only one of them removes a person from the loop.

The rejection of a single number

The most quotable engineering position is about evaluation: a claim that a model scored eighty-three per cent is rejected outright, because one number does not capture result quality — so they work in precision and recall (46:59).

This is worth dwelling on because it is not pedantry. In security work the two error types have wildly different costs. A false negative is a missed intrusion. A false positive is an engineer's afternoon. Any single accuracy figure has averaged those together and thrown away the only information that would let you decide whether the system is usable.

The consequence follows directly from the earlier point. A system with high recall and mediocre precision is exactly the system whose output has to go to a security engineer, which is why the two observations belong together.

Small agents, arranged like an organisation

Their architecture is a set of narrow agents — resource discovery, enumeration, injection testing and others — coordinated by a workflow (45:06). Alongside them sits a set of document-review agents modelled on the company's own meeting culture: a programme manager, a finance reviewer, a product manager, each engaged the way you would engage the corresponding colleague (45:34).

The pattern is worth naming. Each agent is small, which means each can be evaluated against a narrow question, which is the only way the precision-and-recall discipline scales. A single general agent doing all of it would produce results nobody could score.

The advice that actually generalises

The most useful thing said is about adoption rather than technology: the mistake was believing he had to do everything, when the right approach was to pick one tool, apply it to one problem, and iterate (22:24).

Set that against the accessibility argument — there is no barrier to entry, nothing to read, and you can begin in a browser in whatever language you speak (21:02) — and the two form a coherent position. Very low entry cost combined with a narrow first target is a rational strategy under uncertainty about which applications will work.

The scepticism is applied evenly, which is rarer. Negative coverage generates clicks and therefore gets published, which introduces selection bias into the discourse (5:54) — an observation made by someone whose employer has an enormous stake in the technology, about coverage of the technology, and it holds regardless of who is saying it.

关键数据

$0.91 / 7 minutes
cost and runtime for a prototype to complete a security training exercise, eighteen months before the talk 17:45
2 engineers / 48 hours
the effort that produced the working proof of concept 17:16

演讲章节

关键要点

  1. 01

    Most automated security processes still route to human engineers because the results are not good enough to expose to the business. 51:35

  2. 02

    A two-engineer, two-day prototype completed a training exercise in seven minutes for ninety-one cents, eighteen months before the talk. 17:45

  3. 03

    A compile step is the only verification loop discussed that fully removes a person, guaranteeing valid syntax and no invented library calls. 35:38

  4. 04

    He rejects any single accuracy figure outright and insists on precision and recall, because security's two error types have very different costs. 46:59

  5. 05

    His adoption advice is to pick one tool and one problem and iterate, rather than attempting to cover everything. 22:24

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