apache/arrow

What happens to a stranger's pull request here, in the Porchlamp snapshot of 14 October 2026.

Outside pull requests to arrow got a first human reply in a median of 15.3 hours (203 pull requests, 11 April to 8 October 2026); 30% got none within 14 days. It ranks 31 of 3,833 overall and 36 of 1,968 for first-time contributors.

Rating

Score: 73.49
Coverage: 81% · Ceiling A
Tier: A (capped)
Quadrant: Sweet Spot
Ecosystem: systems (C, C++ and Zig)

Capped: this tier can go no higher until more of the project's inputs are measured. It reflects how much data there is, not how good the score is.

Five pillars

Score out of 100, and how much of the pillar was measured
Pillar	Score	Coverage
Responsiveness	65.7	55%
Criticality	65.2	100%
Governance	73.3	100%
Rigor	78.5	100%
Accessibility	95.5	50%

Rank in each lens

Lens	Standing
Balanced	Rank 31 of 3,833
First-timer	Rank 36 of 1,968
Career capital	Rank 23 of 823
Senior systems	Rank 47 of 1,206
AI-assisted	Rank 23 of 3,929

The measured parameters

Parameter	Value	Count	Window	What it measures
Time to First Response	15.2525	203	11 April to 8 October 2026	Median hours from an outside pull request opening to its first substantive human reply.
Decision Rate (90d)	Not shown: Insufficient sample size	—	—	Share of outside pull requests that were merged or closed within 90 days.
First-timer Merge Rate	Not shown: Insufficient sample size	—	—	Share of first-time outside authors' decided pull requests that were merged.
PR Ghost Rate (14d)	0.3	230	16 April to 13 October 2026	Share of outside pull requests with no maintainer response, merge or close within 14 days.
Time to Merge (p90)	559.0314	124	11 April to 8 October 2026	Hours within which 90% of merged outside pull requests were merged.
Dependents	Not shown: Not applicable	—	—	Packages in the registry that depend on this project, counted once each.
OpenSSF Criticality	0.6522	—	—	OpenSSF criticality score from 0 to 1, computed from the project's public activity signals.
Monthly Downloads	Not shown: Not applicable	—	—	Downloads from the package registry in a month.
Legal IP Regime	FOUNDATION_CLA	—	—	The contributor licence regime: DCO, none, a foundation CLA or a corporate CLA.
Elephant Factor	7	971	—	The fewest organisations that account for half of the last year's commits.
Promotion Ladder	AD_HOC	—	—	How openly a contributor can become a maintainer, from closed to verified.
Pipeline Defenses	82.5	—	—	How well the project's build and review pipeline defends against bad changes, 0 to 100.
AI Policy Posture	REGULATED	—	—	Whether the project has a written policy on AI-assisted contributions.
Substantive Review Rate	0.4535	172	11 April to 8 October 2026	Share of decided pull requests that received a substantive review.
Newcomer Issue Supply	12	—	—	Open, unassigned, up-to-date issues marked for newcomers.
Newcomer Conversion	Not shown: Insufficient sample size	—	—	Share of first-time authors whose first pull request merged within 180 days.
Newcomer Return Rate	Not shown: Insufficient sample size	—	—	Share of those merged first-time authors who sent a second pull request within 90 days.
Developer Experience	85	8	—	Developer experience, 0 to 100: half CI run time, half setup signals.

Similar projects

The ranked projects nearest this one in the same ecosystem.

Evidence

Snapshot 2026-10-14, data as of 13 October 2026.
Record hash: 0a7313d99853547d6401a6bae84b6f60e1c84e4374b8fb019f33b0ad118e9499
The full record is in data/2026-10-14/repos/f3.json, under the key apache/arrow.
How every number is measured: Porchlamp methodology.

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