Developer Contribution Quality Analysis

Objective, multi-dimensional analysis of code contribution quality from git data. Produces individual deep-dive reports and team calibration comparisons.

Modern Best Practices

• Measure contribution quality through outcomes (churn, duplication, test coverage), not presence metrics
• AI-assisted code is normal; score the output, not the authorship
• GitClear Diff Delta and CodeScene Code Health are the established commit-level quality benchmarks
• Stanford ghost engineering research claims commit content analysis predicts expert quality judgments (r=0.82); study is not peer-reviewed — apply with caution
• Agent Trace (Cursor RFC) is an emerging vendor-neutral standard for AI attribution
• DX Core 4 framework consolidates DORA/SPACE into a unified set of four oppositional dimensions
• DORA 2025 itself reports AI adoption now correlates with higher throughput and a "mirror and multiplier" pattern (seven team archetypes replace prior elite/high/medium/low clusters); do not confuse it with vendor telemetry reports
• Faros AI's 2026 "Acceleration Whiplash" telemetry report (4,000+ teams, distinct from DORA) found bugs per developer up 54% and incidents per PR up 242.7% where AI adoption outran test/review discipline — cite it as Faros, not DORA
• GitClear Jan 2026 (2,172 developer-weeks): power AI users produced 4.2x more durable code than non-users but also showed 9x more churn — AI widened an existing performance gap and its downside, not evidence of uniform uplift
• GitClear "The Maintainability Gap" 2026 (623M code changes) extends this: refactor/moved-code share collapsed to 3.8% YTD 2026 (13% in 2023), copy/paste 15.7% in H1 2026, error-masking constructs +47%, cross-file reuse -35% — use these as the current structural-quality benchmarks
• Treat commits and PRs authored end-to-end by an autonomous coding agent (not just AI-assisted) as a distinct evidence class — see Known Traps

Quick Reference

Task	Tool / Reference	Command / Path	When
Extract contribution profiles	extract-contribution-profile.py	python scripts/extract-contribution-profile.py --config config.json	First step after CSV extraction
Sample code quality	sample-code-quality.py	python scripts/sample-code-quality.py --config config.json	When repo checkouts available
Generate quality report	generate-quality-report.py	python scripts/generate-quality-report.py --config config.json --mode person	After profile extraction
Understand scoring model	scoring-model.md	references/scoring-model.md	Before interpreting results
Map findings to CC-* rules	code-quality-sampling-rubric.md	references/code-quality-sampling-rubric.md	During code sampling
Calibrate against industry	industry-benchmarks.md	references/industry-benchmarks.md	When comparing to external norms

When to Use This Skill

• Engineering managers assessing individual contribution patterns
• Tech leads reviewing code quality trends across a team
• CTOs building engineering scorecards
• Pre-promotion or performance-review technical calibration
• Measuring AI-assisted development quality impact
• Identifying skill gaps or coaching targets

When NOT to Use This Skill

• Governed multi-signal risk triage -> the project-scoped counterpart skill
• Defining code quality rules -> software-clean-code-standard
• AI coding tool ROI or adoption tracking -> dev-ai-coding-metrics
• Repository-level code health (not person-level) -> qa-refactoring
• General code review workflow -> software-code-review

Defaults

• Measure contribution quality, not presence or working hours
• Quality is multi-dimensional; no single number replaces the 6-dimension profile
• Compare against personal baseline first, then team, then industry
• AI-assisted code is quality-neutral; measure outcomes (churn, duplication, test coverage) regardless of authorship
• Git data is necessary but not sufficient; always note what evidence is missing
• CC-* rules from software-clean-code-standard are the code quality rubric
• Minimum data: 30 commits and 20 active days in the analysis window
• Scripts consume the same CSV format as the project-scoped counterpart skill extraction
• Ingest dedupes on (repo, commit_hash) and cancels Revert "X" + original pairs (both flagged net_cancel) so churn-rate and net_lines do not double-count multi-root scans or self-reverting churn
• Code volume is measured as code_loc (extension-filtered: drops .json, .yaml, .md, snapshots, generated paths). Raw net_loc and churn_loc are kept for context but never feed the headline rating.
• The D2 headline rating is complexity-weighted: code_loc × (1 + α·ΔCC + β·novelty), banded against team median with role calibration. Definition is shared with the project-scoped counterpart skill; both skills must produce identical ratings from the same CSV input.

Workflow

1. Define the question — quality audit, growth tracking, team calibration, or promotion case
2. Set scope — person(s), time window, repo roots
3. Extract git + MR data — use the project-scoped counterpart skill extraction scripts or provide CSVs in the same format
4. Run contribution profile analysis — extract-contribution-profile.py computes all Tier 1 signals
5. Run code quality sampling (optional) — sample-code-quality.py maps sampled commits to CC-* rules
6. Generate quality report — generate-quality-report.py in person or team mode
7. Present findings with explicit limitations and calibration context

ASCII Flow

contribution quality request
  -> define decision: audit, growth, calibration, promotion, or AI impact
  -> set people, time window, repos, and minimum data threshold
  -> extract and normalize git plus MR/PR evidence
  -> dedupe commits and cancel revert pairs
  -> compute contribution profile and role-aware baselines
  -> sample code quality against CC-* rules when repo checkouts exist
  -> generate person, team, scorecard, or JSON output
  -> present limitations and calibration context

Fact-Checking

• Known bugs, regressions, framework/compiler/runtime footguns, and version-specific crash or workaround guidance must be verified against current primary web sources before being treated as current fact.
• Verify current external benchmark claims, vendor metrics, and framework standards against primary sources before presenting them as current fact.
• Treat vendor-authored scoring systems, AI attribution standards, and industry benchmark comparisons as volatile unless rechecked against current documentation or published research.
• If web verification is unavailable, label time-sensitive benchmark or standards guidance as unverified.

Decision Tree: Assessment Type

What is the assessment goal?
├── Individual quality audit?
│   ├── Point-in-time snapshot → person quality report
│   └── Trend over time → person trend report (multiple windows)
├── Team quality comparison?
│   ├── Promotion / review calibration → team calibration report
│   └── Quality trend monitoring → team trend report
└── AI impact assessment?
    └── Before/after or AI-ratio analysis → quality-neutral outcome comparison

Scoring Model (Summary)

Six dimensions, 100 total points. See references/scoring-model.md for full detail.

#	Dimension	Weight	Primary Signals
D1	Delivery Consistency	20	Commit frequency stability, active days, MR throughput, trend
D2	Code Quality Signals	25	Churn rate (14d), duplication, refactoring ratio, complexity-weighted rating (code-only LOC × ΔCC + novelty), CC-* compliance
D3	Commit Craft	15	Message quality, scope discipline, PR size, self-merge rate
D4	Review & Collaboration	20	Review participation, responsiveness, cross-repo contribution
D5	Test & Safety Practices	10	Test-to-code ratio, test presence in features, security-file awareness
D6	D6 Context-Only Signal — AI Development Quality	—	Annotation only: AI code survival, quality parity, verification burden

Quality Tiers (D1-D5, 90 pts total): A (72-90 Exemplary), B (54-71 Solid), C (36-53 Developing), D (0-35 Concerning)

D6 carries no point allocation and is excluded from tier assignment. It is appended to reports as a separate annotation. See references/scoring-model.md for rationale.

Output Modes

• Person quality report — individual deep-dive with 6-dimension breakdown, sampled commit quality, CC-* findings
• Team calibration report — comparison matrix with heatmap, tier distribution, team strengths/gaps
• Quality scorecard — one-page quick reference for presentations
• Machine-readable JSON — contribution-profiles.json for dashboards and downstream tools

Known Traps

• Treating commit frequency or online presence as contribution quality when the actual question is code-health and delivery outcomes.
• Comparing developers across very different repo types, support load, or code ownership without first calibrating those constraints.
• Interpreting AI-heavy contribution patterns as automatically higher or lower quality without reviewing churn, survival, and verification burden.
• Building a score from sparse data windows that do not meet the minimum threshold for stable signal extraction.
• Sampling code quality from convenience commits instead of representative work, which biases the conclusions toward visible or recent changes.
• Scoring a PR that was generated end-to-end by an autonomous coding agent (Devin, Codex cloud tasks, Claude Code background/delegated sessions) as if it reflects the human's craft. When a repo's provenance data shows fully agent-authored diffs merged under a human identity, D3 (Commit Craft) and D2 code-surface signals measure the agent's output and the human's review/orchestration judgment, not their hand-written code quality — say so explicitly in the report and do not fold it into an unqualified craft score.
• Letting a rising headline number go unquestioned when the underlying behavior could be gamed: churn can be suppressed by avoiding risky files instead of writing more durable code; PR-size discipline can be gamed by artificially splitting one change into many trivial PRs; test-to-code ratio can be inflated with low-value snapshot or no-op tests. Cross-check any single improving metric against at least one adjacent signal before crediting it.

Common Anti-Patterns

• Turning a multi-dimensional quality model into a hidden ranking engine and pretending the composite number is objective truth.
• Using the analysis for attendance policing or concurrent-employment inference when the skill is supposed to measure contribution quality.
• Treating one period’s score as a permanent trait rather than a snapshot with scope, context, and missing evidence.
• Comparing people on absolute numbers without anchoring against their own baseline and the team’s expected role shape.
• Letting the report imply causality or promotion readiness when the evidence only supports calibration and coaching discussion.
• Letting duplicate (repo, commit_hash) rows or Revert "X" pairs inflate churn and net_lines; the ingest layer must dedupe and cancel revert pairs before D2 scoring.

Integration

Data Pipeline (supplier: the project-scoped counterpart skill)

This skill consumes the same CSV format produced by:

• extract-commits.sh → raw-commits.csv
• extract-mr-acceptances.sh → mr-acceptances.csv

It also reuses the identity-aliases.json format and email_to_person config pattern. It does NOT duplicate extraction scripts or authenticity triage.

Code Quality Rubric (consumer: software-clean-code-standard)

Sampled commit findings reference CC-* rule IDs (CC-NAM-01 through CC-DOC-04) and use the same P0-P3 priority system. No rule definitions are duplicated.

Navigation

Resources

• Scoring Model — 6-dimension point model (D1-D5 scored, D6 annotation only); weights, thresholds, tier override rules
• Contribution Signals Catalog — all signals grouped by extraction tier (git-only, static analysis, AI attribution) with confounders
• Code Quality Sampling Rubric — P0-P3 CC-* rule mapping for sampled commits; automated check confidence levels
• AI Attribution Patterns — ground-truth tooling, detection heuristics, quality metrics for AI-assisted code (all context-only)
• MR/PR Quality Signals — rubber-stamp detection, size/review-speed/rework benchmarks and thresholds
• Industry Benchmarks — GitClear (2020-2024 baseline, 2026 cohort), DORA 2024/2025, METR, Stanford calibration data

Templates

• Person Quality Report
• Team Calibration Report
• Quality Scorecard

Scripts

• Pipeline README — setup, CSV format spec, usage
• Config Example
• Extract Contribution Profile
• Sample Code Quality
• Generate Quality Report

Related Skills

• the project-scoped counterpart skill — authenticity triage and governed risk signal convergence (upstream)
• software-clean-code-standard — CC-* rule definitions and code review standards (rubric source)
• dev-ai-coding-metrics — AI tool adoption and ROI measurement (complementary)
• software-code-review — review workflow and judgment (process)

Learnings Loop

Before applying this skill on a non-trivial task, read learnings.consolidated.md in this directory (and learnings.md if present).

After applying it, if you encountered a pattern worth remembering, a mistake worth preventing, or a domain fact that surprised you, append one dated bullet to learnings.md via agents-skills-feedback-loop/scripts/append_learning.py. Do not modify SKILL.md itself.