UK Public Sector GitHub Observatory
GOV.UK publishes its engineering standards at docs.publishing.service.gov.uk - 986 pages and 1.5m words of it. That makes an unusual experiment possible: take the written conventions, turn them into file-system tests, and run them against the repositories they govern. This page is the result.
The documentation
What stands out
Among the 118 repositories the developer documentation covers, 77% carry the prescribed ci.yml and 80% configure Dependabot. Among the 309 live repositories it does not cover, those figures fall to 5% and 23%. Documentation and compliance travel together - the question is which causes which.
Only 6% of documented repositories carry a CODEOWNERS file, against 9% of undocumented ones. That is not a gap in the core so much as a different solution to the same problem: GOV.UK publishes ownership centrally, mapped to a team and an alerting channel, rather than declaring it per repository in a file GitHub reads.
118 of 269 manual pages carry an automated warning that they have not been updated recently. That is unusually honest for internal documentation, and far better than silent staleness, but it means roughly two in five pages of the standard cannot be relied on without checking the code.
Each maps to a Slack channel, and a separate alerting channel. This is the single most valuable thing in the developer documentation: for the core platform, 'who owns this?' has a published answer - something most organisations of this size cannot produce.
Compliance where the docs apply
The 118 documented repositories
Each row is a convention stated in the manual, tested against the file tree at HEAD.
Compliance where they do not
The 309 live but undocumented repositories
The same tests, run against live repositories the developer documentation does not cover. The gap between this chart and the one above is the real finding.
The shared-gem strategy
GOV.UK gem adoption among documented repositories
The manual asks teams to build on a set of published gems rather than reinventing common needs. Counted by direct reference in each Gemfile.
The architectural centre
Repositories most referenced across the documentation
How often each repository is linked from the documentation, excluding the docs repo itself. This is a fair proxy for architectural centrality: publishing-api and content-store are the spine of GOV.UK, and the documentation cannot describe much without pointing at them.
Ownership and taxonomy
Repositories per owning team
As published in the developer documentation.
Repositories per official type
GOV.UK's own classification of its estate.