AWS re:Invent 2025

There Is a Fast Path to Reliability and a Slow One

原演讲者: Lori Knapp, Principal Product Manager, Amazon AGI · Amazon

来源已核验演讲日期待核实session41:07EN3 分钟阅读

Most enterprise pilots sit on the unverifiable side of the divide while being managed with expectations borrowed from the verifiable one.

The most useful sentence in this session is about where reliability is achievable: for workflows calling well-structured interfaces and producing code that can be checked, the path to reliability is faster (17:10).

The implication is the part worth extracting. There is a slower path, and it is the one everyone else is on.

Verifiability as the sorting criterion

The framing divides agent work into two categories that look similar and behave completely differently.

In the first, the output can be checked mechanically. Code compiles or does not. An interface call returns a valid response or an error. A test passes. Reliability here is an engineering problem: measure, find the failures, fix them.

In the second, correctness is a judgement. Whether a summary captured the right points, whether a recommendation was appropriate, whether the tone was suitable for the customer. No mechanical check exists, so every improvement claim rests on sampling and human review — which is slow, expensive, and does not scale with the number of workflows.

Most enterprise pilots are in the second category and are being managed with expectations from the first. The session names the distinction and then spends most of its time on the easier side.

The testing idea that generalises

The best illustration comes from browser automation: rather than examining the markup the way a conventional test would, the system looks at what the customer would actually observe — walking through checkout and booking flows, and identifying revenue leakage (25:49).

That reframing is more portable than the specific application. A conventional interface test asserts on structure, which is a proxy for what the user sees and breaks whenever the structure changes for reasons that do not matter. Asserting on the observable outcome tests the thing you care about.

The revenue-leakage framing is the sharper part. It defines success in the business's own terms rather than in engineering ones, which means the test measures whether the flow works commercially rather than whether the elements are present. That also makes it verifiable in the good sense — money either arrives or it does not.

What the capability numbers actually change

Two figures are offered as headline capabilities and deserve different treatment.

The demonstration workflow makes roughly fifteen to twenty tool calls to understand an issue, locate the changes needed, and make them (12:29). That count is the honest measure of what agentic means — not one clever response but a chain of twenty decisions, each of which can be wrong and each of which the next depends on.

The context length of up to a million tokens, described as enabling something like a hundred thousand lines of code, four-hundred-page documents, or ninety-minute videos (13:56), is the more heavily promoted number and the more ambiguous one. Capacity to accept that much input is not the same as attending to it well, and the session does not distinguish them.

The two figures interact in a way that is not discussed. Twenty sequential tool calls each returning substantial output is how a context fills, which means large windows are less about ingesting one enormous document and more about surviving a long chain of moderate ones.

The layer they are right to emphasise

The architectural point is that models sit on top of infrastructure — tool orchestration, memory for managing context, and observability for monitoring behaviour (4:11) — and that not every model handles agentic work equally well, since the requirement is decomposing a task, planning, and calling tools reliably (4:42).

The progression they use to explain this is clarifying. Coding moves from explaining an error, to generating an artefact, to writing code, running tests and deploying a fix (2:51). Support moves from summarising issues for a human, to a first-line interface, to something that resolves the issue (3:18).

Each step transfers a decision from the person to the system. The final step in each is where the verification question becomes unavoidable — and where the earlier distinction decides whether you are on the fast path or the slow one.

关键数据

15-20 tool calls
the chain length in the demonstrated code-change workflow 12:29
1 million tokens
context length, described as roughly 100,000 lines of code or a 400-page document 13:56

演讲章节

关键要点

  1. 01

    Where interfaces are structured and output is verifiable, the path to reliability is faster — implying a slower path everywhere else. 17:10

  2. 02

    Browser testing examines what a customer would observe rather than the markup, and defines success as revenue leakage rather than element presence. 25:49

  3. 03

    The demonstrated workflow makes fifteen to twenty tool calls, which is the honest measure of what an agentic chain involves. 12:29

  4. 04

    Context of up to a million tokens is offered as capacity, without distinguishing capacity from attention quality. 13:56

  5. 05

    Not all models handle agentic work equally, since the requirement is decomposing a task, planning, and calling tools reliably. 4:42

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