Internal Developer Platform  ·  View 05 of 21  ·  People and journeys

Journey — Drive a Change Across 1,400 Components

The journey that decides whether twelve platform engineers can serve nine hundred.

Editable source SVG draw.io All views
Platform Engineer one of twelve Goal — Retire a template version everyone is still on, without becoming the reason a team missed a release Trigger — A base image reaching end of support in 90 days Done when — Zero components below the supported floor, and no ticket raised to get there 1 · Measure who is where 2 · Publish new version 3 · Automate 1,180 PRs 4 · Chase the tail ◆ moment of truth 5 · Enforce ◆ moment of truth 6 · Retire What they do Reads the drift report Ships template v9 Opens the update PRs Talks to 40 teams Sets the floor to v8 Deletes v7 Where Adoption dashboard Template registry Bot PRs Chat · office hours Policy bundle Changelog What the platform does 1,180 track · 220 fork Canary component first PR per tracking repo Nothing — forks manual Advisory, then binding Drift returns to zero How it feels In control Working Stuck Where it hurts PR fatigue in teams 220 forks, by hand Feels like a mandate User Journey — Platform Engineer Drives a Change Across 1,400 Components The trough is the forked tail: 16% of components absorb most of the migration effort. That ratio, not the portal, is what decides whether twelve engineers can serve nine hundred. v 1.0 · owner Platform Architecture · date 2026-09

The trough

  • The forked tail. An assumed 16% of components do not track their template, and they absorb most of the migration effort because nothing can be automated for them.
  • This is the cost side of the fork decision in ADR-03: autonomy for the team is bought with platform-team time, and the ratio is the number to watch.
  • Enforcement at the end reads as a mandate even when the path is genuinely optional — which is why the deprecation window is published before the first pull request, not after the deadline.

Assumptions

  • 1,180 tracking, 220 forked, a 90-day supported-floor window (stated assumptions).
  • Automated update pull requests are acceptable into product repositories — an organisational assumption, not a technical one.

What this demands

  • Template version recorded on every component, or the drift report is fiction (ADR-03).
  • A canary component per golden path that walks the whole path continuously, so a broken template is caught before 1,180 pull requests carry it (ADR-14).
◀  Journey — Create and Ship a New Service All views Journey — Debug a Service the Platform Generated  ▶
Solution Architecture v1.0 · Microsoft Azure · Platform Architecture · 2026-09 · 21 views · 16 architecture decision records05-journey-platform-migration