UK Public Sector GitHub Observatory
Every commit carries an author name and email. Collapsing 50,846 per-repository author records by email gives 3,966 distinct identities - 3,649 people and 317 machines. Identity is keyed on email because it is the only stable key git offers; one person using both a work and a personal address will appear twice.
People
What stands out
36 people out of 3,649 account for 349.7k commits. The top ten alone wrote 9%. This is the usual open-source power law, but it is worth noting in a government context: institutional knowledge is concentrated in very few hands.
442 of 3,649 committers made a single commit and never returned. 40% touched only one repository. A public organisation attracts drive-by contributors, and the numbers show GDS accepted them.
Weekday work dominates, as you would expect from a civil-service delivery organisation with a strong stated position on sustainable pace. The residual weekend activity is concentrated in incident response and personal-time open-source work.
329.7k commits come from 317 automated identities - overwhelmingly Dependabot. GOV.UK's documented policy is to auto-merge dependency upgrades where possible, and the commit history shows that policy working at scale.
In 175 of the 919 live repositories with meaningful history, one individual wrote more than half of all commits. That is the ordinary shape of a large estate with many small tools, but it is worth knowing which ones - they are listed below.
Who writes the code
Top 25 committers by commit count
Humans only. Bots are charted separately below.
Who they work for
Committers by email domain
A rough proxy for employment. GDS staff use gov.uk addresses; GitHub's privacy setting hides the rest, and a long tail commit from personal accounts.
Churn and tenure
Distinct people committing each year
Counting anyone whose active span covers that year. The shape tracks GDS headcount and the delivery peaks of the mid-2010s.
How long people stay
Span from first to last commit anywhere in the org.
When the work happens
Commits by hour of day
Author local time as recorded in the commit. A clean single-peak working day.
Commits by day of week
Reading the pattern
Weekend commits account for 2.0% of all activity. The working day peaks between 10:00 and 16:00 with a visible lunch dip, and tails off sharply after 18:00 - the signature of an organisation that does not run on overtime.
Concentration of knowledge
For each live repository with more than fifty human commits, how many people it takes to account for over half of them. One is a genuine key-person risk; four or more is a healthily shared codebase. 919 repositories qualify for the measure.
Bus factor across live repositories
Fewest contributors accounting for more than half the commits.
Where a single person wrote most of it
Share of commits by the largest single contributor, for the most concentrated repositories.
The machines
Top automated committers
Dependabot dominates. GOV.UK runs an in-house govuk-dependabot-merger service that auto-merges qualifying upgrade PRs, which is why bot commit volume is so high.
Top 60 committers
| Committer | Email type | Commits | Repos | First | Last | Years |
|---|---|---|---|---|---|---|
| petergphillips | other-org | 27,204 | 218 | 2018-10 | 2026-08 | 7.9 |
| Andrew Pearce | gov.uk | 16,194 | 54 | 2018-02 | 2026-08 | 8.5 |
| Aaron Robinson | gov.uk | 15,366 | 52 | 2021-03 | 2026-08 | 5.4 |
| Elvis Ciotti | gov.uk | 14,793 | 5 | 2015-01 | 2018-12 | 3.9 |
| Paul Solecki | gov.uk | 12,956 | 107 | 2019-06 | 2026-08 | 7.1 |
| Marcus Aspin | other-org | 12,155 | 150 | 2018-06 | 2026-08 | 8.2 |
| Alex Saunders | gov.uk | 11,587 | 20 | 2019-03 | 2026-08 | 7.5 |
| Anthony Britton | gov.uk | 11,415 | 92 | 2022-05 | 2026-08 | 4.2 |
| Andrew Lee | gov.uk | 11,359 | 224 | 2019-04 | 2026-08 | 7.4 |
| Nick Davis | gov.uk | 11,076 | 13 | 2020-07 | 2026-07 | 6.0 |
| Igor | gov.uk | 11,069 | 52 | 2015-05 | 2026-03 | 10.8 |
| Elliot Smith | gov.uk | 10,889 | 25 | 2020-11 | 2026-08 | 5.7 |
| Jesus Laiz | gov.uk | 10,732 | 57 | 2016-06 | 2026-08 | 10.2 |
| Greg Tyler | gov.uk | 10,582 | 78 | 2019-03 | 2026-08 | 7.4 |
| Joshua Hawxwell | gov.uk | 10,524 | 31 | 2020-03 | 2026-08 | 6.4 |
| Michael Willis | gov.uk | 10,194 | 142 | 2017-05 | 2026-08 | 9.3 |
| Mike Halma | gov.uk | 9,705 | 117 | 2019-11 | 2026-08 | 6.7 |
| Colin Bruce | gov.uk | 9,569 | 26 | 2014-05 | 2026-08 | 12.3 |
| Jacob Woffenden | gov.uk | 8,598 | 94 | 2020-09 | 2026-08 | 6.0 |
| Andy Marke | gov.uk | 8,558 | 95 | 2017-11 | 2026-08 | 8.7 |
| David Salgado | gov.uk | 8,524 | 112 | 2016-07 | 2021-02 | 4.6 |
| jasonBirchall | gov.uk | 7,953 | 173 | 2018-02 | 2026-08 | 8.5 |
| Dominic Robinson | gov.uk | 7,919 | 17 | 2020-10 | 2026-08 | 5.9 |
| dms1981 | gov.uk | 7,606 | 49 | 2022-01 | 2026-08 | 4.6 |
| Antony Bishop | github-private | 7,525 | 72 | 2019-03 | 2026-08 | 7.4 |
| Carlo Veo | gov.uk | 6,432 | 56 | 2023-09 | 2026-08 | 2.9 |
| davidatkinsuk | gov.uk | 6,353 | 28 | 2023-12 | 2026-08 | 2.7 |
| steverendell | github-private | 6,228 | 53 | 2017-10 | 2026-08 | 8.8 |
| David Winchurch | gov.uk | 6,094 | 47 | 2017-04 | 2026-08 | 9.3 |
| Jake Mulley | github-private | 6,073 | 120 | 2020-08 | 2024-01 | 3.4 |
| Poornima Krishnasamy | gov.uk | 5,937 | 96 | 2019-06 | 2024-06 | 5.0 |
| Chris Pymm | gov.uk | 5,812 | 12 | 2022-01 | 2026-08 | 4.6 |
| Dom Smith | gov.uk | 5,787 | 42 | 2013-10 | 2021-08 | 7.9 |
| EarthlingDavey | github-private | 5,757 | 28 | 2024-01 | 2026-08 | 2.6 |
| Matt | gov.uk | 5,627 | 186 | 2018-02 | 2026-08 | 8.5 |
| rossdowthwaite | personal | 5,551 | 10 | 2023-11 | 2026-08 | 2.7 |
| Paul Massey | gov.uk | 5,487 | 45 | 2017-06 | 2026-08 | 9.2 |
| Brett Minnie | other-org | 5,363 | 63 | 2014-03 | 2022-02 | 8.0 |
| Neil Smith | gov.uk | 5,314 | 21 | 2014-07 | 2019-09 | 5.2 |
| Fred Marecesche | gov.uk | 5,283 | 46 | 2015-01 | 2026-08 | 11.6 |
| Joel Sugarman | gov.uk | 5,266 | 30 | 2015-04 | 2026-08 | 11.3 |
| Patrick Gleeson | gov.uk | 5,004 | 13 | 2022-09 | 2025-10 | 3.1 |
| Nathan Russell | gov.uk | 4,948 | 22 | 2021-11 | 2026-08 | 4.7 |
| Jon Brighton | gov.uk | 4,919 | 124 | 2019-10 | 2026-08 | 6.8 |
| carlov20 | github-private | 4,898 | 79 | 2021-06 | 2023-06 | 2.0 |
| jaskaransarkaria | gov.uk | 4,896 | 87 | 2021-11 | 2026-06 | 4.5 |
| Biggs Thorarensen | other-org | 4,874 | 10 | 2015-11 | 2018-09 | 2.9 |
| thomas.geraghty | github-private | 4,857 | 63 | 2023-11 | 2026-08 | 2.8 |
| adam | gov.uk | 4,805 | 61 | 2016-11 | 2026-08 | 9.7 |
| Matt Crowson | gov.uk | 4,792 | 27 | 2020-01 | 2026-08 | 6.6 |
| brenetic | github-private | 4,772 | 45 | 2020-02 | 2023-06 | 3.4 |
| charlesmmarshall | gov.uk | 4,767 | 43 | 2020-06 | 2026-08 | 6.2 |
| David Lantos | gov.uk | 4,762 | 52 | 2018-06 | 2026-01 | 7.6 |
| George Taylor | gov.uk | 4,646 | 34 | 2023-02 | 2025-01 | 1.9 |
| karenmillermoj | gov.uk | 4,637 | 49 | 2020-12 | 2026-08 | 5.7 |
| Stephen Dicks | gov.uk | 4,635 | 19 | 2019-07 | 2024-12 | 5.4 |
| Mark Rees | gov.uk | 4,612 | 41 | 2021-01 | 2026-08 | 5.6 |
| Aldo "xoen" Giambelluca | gov.uk | 4,584 | 47 | 2017-02 | 2026-07 | 9.5 |
| David Elliott | gov.uk | 4,540 | 54 | 2017-02 | 2026-08 | 9.5 |
| Alex Robinson | other-org | 4,538 | 59 | 2017-01 | 2020-12 | 3.9 |