Golden Paths and Phase Gates Across Decision-Ladder Levels

A platform reference architecture says which components are shared. It doesn’t say what a team building on top of it is actually allowed to do at each decision-ladder level, and without that, delivery pressure will find the gap. Golden paths are standardized routes that bundle the minimum artifacts and phase gates required to operate safely at a given decision-ladder level. Require repeatable evidence for quality, security, observability, and cost controls before a capability reaches production. Do not let a team skip evaluation or approval when moving from prompting-only to retrieval, tools, or agents.

Hold a few requirements fixed across every path. Regulated data must stay inside a defined trust boundary. Access must be least-privilege and auditable. A production change must be reversible without waiting on a bespoke expert intervention. Delivery still needs to move quickly, so a golden path defines what’s allowed by default at every level and what evidence must exist to justify stepping up. Track three measurable outcomes throughout: a stable quality SLO, bounded spend, and a reviewable chain of design decisions.

A golden path pairs an allowed component set with a small bundle of required artifacts that travel with the workload. At minimum, bundle an architecture decision record (ADR-<id>), a non-functional requirements set (NFR-<id>), an evaluation specification (eval-spec-<id>) pointing to an approved golden dataset, and a security packet pointer with a threat model reference and a data classification statement. A phase gate consumes these artifacts as evidence. Tie every gate to a risk tier and a quality SLO, so the gating decision tests whether the evidence is sufficient for the intended blast radius, not whether the implementation style is fashionable.

The following table shows a matrix view of ...