Architects, Platform Engineers and Site Reliability Engineers

All courses / AI Developer / Module 3 / Chapter 16

Learning objectives

After the lesson the participant can:

Explain what the architect keeps and what the developer's team keeps, and how a tool's proposal is routed between them
Design the four AI tooling defaults a platform team provides: allow-list, route, logging and cost, and supply chain
Explain how a spent error budget lowers the level of delegation for AI-originated change
Draft a golden-path specification with gates, tools, an exception route and an error-budget rule

Key concepts

A proposal that is an architectural change: A tool that proposes a dependency, an endpoint or a permission has proposed an architectural change. A code-ownership rule on those files routes the proposal to the architect's forum instead of letting it pass as an ordinary diff.
Golden path with AI tooling defaults: The opinionated and supported path to build something. The platform team adds four defaults: an allow-list of assistants and agents, a route through the AI gateway, logging and cost by team, and a supply-chain rule that reports a refusal as well as making it.
Exception route: A golden path made mandatory without an exception route makes teams with a real need leave quietly. An exception therefore has a named approver and an expiry date, and the specification says what happens at expiry.
Error budget connected to the ladder: The book's own conclusion: when a service's error budget is spent, the level of delegation for AI-originated change in that service drops. The rule lowers delegation by class and not by person, so nobody's performance is read from it.

Interactive exercises

Do them here and get feedback at once. Choose a card and then where it belongs, or drag it.

Interactive exercise 1 · Match

Who decides what among the neighbours

Match each decision to the role that decides it in the chapter's table of boundaries and handovers.

Interactive exercise 2 · Scenario

A team wants to leave the golden path

Apply what the chapter says about exceptions to the golden path.

Teaching plan

15 min	Lecture on the three neighbours and their shared problem, with the table of decisions: who decides, who builds, who runs or stops, and under what constraint.
15 min	The teacher walks through the golden-path specification of Nordvik Region (AIDR-1116) and the error-budget rule of Hansa Mutual (AIDR-1166), stressing what neither claims.
10 min	Participants identify, for their own organisation, who can disable a tool's route and who owns the definition of a pipeline gate.
25 min	Exercise: groups write a golden-path specification with AI tooling defaults by the eight steps of the practical guide.
10 min	Plenary on concentration risk: what a team of seven that writes the gates, reviews agent-drafted code and runs the gateway can do about it.

Discussion

Neither organisation has a rule that says which decisions need the architect. What rule would you write, and how would a tool's proposal trigger it?
The Nordvik specification records the question whether prompts are records as open rather than settling it by default. Why does that matter for what the gateway logs?
The chapter says both organisations can state what the path contains and who owns it, and that this is a smaller claim than saying the platform governs AI tooling. What evidence would support the larger claim?

Written exercise

Exercise · 25 minutes

A golden-path specification with AI tooling defaults

Write a golden-path specification for one kind of service in your organisation, or for the Spring service path of Nordvik Region's platform team. Name the path, its version, its owner, the person accountable for use and the delegation profile that applies. List the pipeline gates and who owns their definitions, and state that no coding agent has write access to them. List each allowed AI tool with usage mode and route. State what the gateway records and what it does not. Write the supply-chain rule, including who is told about an unknown package name. Write the exception route with approver and expiry, the error-budget rule and a review date.

Deliverable: A golden-path specification with owner, gates, allowed tools, gateway logging, supply-chain rule, exception route, error-budget rule and review date.

Your work

Self-test

Choose an answer to see whether it is right, or open the answer below each question.

Under the error-budget policy recorded in AIDR-1166 for the customer portal of Hansa Mutual, what happens to the Level 3 Bounded class when the service budget is spent?
Show the answer
C. It drops from Level 3 Bounded to Level 2 Supervised for that service
The table across the degrees of delegation shows patch-level dependency updates at Level 3 Bounded under MND-HM-DEV-01 and Level 2 Supervised when the service budget is spent: delegation is lowered by class, not by person.
What does the chapter's decision table say about the definition of a pipeline gate?
Show the answer
B. The platform lead decides it, and it is not editable by the change it gates
The platform lead decides, the platform team builds and runs the gate, and the constraint is that the definition is not editable by the change it gates and no agent has write access.
Which of these does the chapter list as a common failure of a platform team?
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D. Making the golden path mandatory without an exception route
The first of three common failures is a mandatory path with no exception route, so that teams with a real need leave quietly, which is the situation the golden path was meant to prevent.