contributor-analyzer

name	contributor-analyzer
description	Analyzes engineering contributors for annual reviews, progress tracking, and production ownership. Reads every commit diff (not sampling), calculates accuracy rates, assesses engineering maturity through qualitative judgment, and generates promotion-ready performance reviews. Works with any git repository using local git for commit analysis and gh CLI for GitHub PR/review metadata.
license	MIT
compatibility	Requires git (local repository access) and gh (GitHub CLI) for full analysis. Optional: jq for JSON parsing, bc for arithmetic.
metadata	{"author":"anivar","version":"1.0.0","tags":["contributor-analysis","annual-review","code-quality","production-ownership","promotion","engineering-maturity"]}

Contributor Analyzer

Unified skill for engineering contributor analysis. Combines annual review generation, historical progress tracking, production ownership mapping, and qualitative judgment — all driven by reading actual commit diffs.

Skill Format

Each reference file covers one analysis concern:

• Quick Reference: Summary tables and key thresholds
• Process Steps: Bash commands and orchestration
• Templates: Output formats for reports and profiles
• Deep Dive: Full context with examples from real-world 1,091-commit analysis

Impact ratings: CRITICAL (blocks accuracy), HIGH (major insight), MEDIUM (enriches analysis)

When to Apply

Reference these guidelines when:

• Running annual or quarterly performance reviews
• Assessing promotion readiness with evidence
• Tracking contributor progress over time (incremental updates)
• Mapping production code ownership and risk
• Comparing multiple engineers for team decisions
• Identifying single points of failure in codebase ownership

Priority-Ordered References

Priority	Reference	Impact	Description
1	agent-context-management.md	CRITICAL	Batch sizing, file-based output, context budget
2	annual-review-process.md	CRITICAL	7-phase analysis: identity, metrics, diffs, bugs, quality, report, comparison
3	accuracy-analysis.md	HIGH	Bug introduction detection, accuracy rate calculation, benchmarks
4	code-quality-catalog.md	HIGH	Anti-pattern catalog (9 patterns) and strength catalog (8 patterns)
5	qualitative-judgment.md	HIGH	Engineering wisdom, situational decisions, growth trajectory
6	report-templates.md	HIGH	Report sections, rating scale, promotion framework, comparison format
7	production-ownership.md	MEDIUM	Production branch ownership, domain map, SPOF detection
8	historical-progress.md	MEDIUM	Incremental profiles, plateau detection, period-over-period tracking

Quick Reference

Critical: Context Management

Before launching ANY analysis, count commits:

git log --author="EMAIL" --after="YEAR-01-01" --before="YEAR+1-01-01" --oneline | wc -l

Batch sizing (hard limits from real failures):

Commits	Action
1-40	Read in main session
41-70	Single sub-task, writes findings to file
71-90	Split into 2 sub-tasks
91+	WILL FAIL — split into 3+ or monthly sub-tasks

Sub-tasks write to files, return 3-line summaries. Never return raw analysis inline.

Critical: Annual Review Process

7 phases, sequential:

1. Identity Discovery — find all git email variants
2. Metrics — commits, PRs, reviews, lines (git + gh CLI)
3. Read ALL Diffs — quarterly parallel sub-tasks, file-based output
4. Bug Introduction — self-reverts, crash-fixes, same-day fixes, hook bypass
5. Code Quality — anti-patterns and strengths from diff reading
6. Report Generation — structured markdown with rating + promotion assessment
7. Comparison — multi-engineer ranking with evidence

High: Accuracy Rate

Effective Accuracy = 100% - (fix-related commits / total commits)

Rate	Assessment
>90%	Excellent
85-90%	Good
80-85%	Concerning
<80%	Poor — significant rework

High: Tool Separation

• Local git: ALL commit-level analysis (log, show, diff, blame, shortlog)
• gh CLI: ONLY for PR counts, review counts, user verification
• Never use gh to read diffs — local git is faster with no rate limits

References

Full documentation with process steps and templates in references/:

Analysis Process

File	Impact	Description
annual-review-process.md	CRITICAL	Complete 7-phase review process with bash commands
agent-context-management.md	CRITICAL	Batch sizing, file-based output, multi-engineer orchestration
accuracy-analysis.md	HIGH	Bug detection commands, accuracy formula, benchmarks
code-quality-catalog.md	HIGH	9 anti-patterns + 8 strengths with severity/significance

Judgment & Assessment

File	Impact	Description
qualitative-judgment.md	HIGH	Engineering wisdom indicators, growth trajectory, promotion signals
report-templates.md	HIGH	Required report sections, rating scale, comparison format

Ownership & Progress

File	Impact	Description
production-ownership.md	MEDIUM	Production file identification, domain map, SPOF detection
historical-progress.md	MEDIUM	Incremental profiles, plateau detection, cumulative profiles

Searching References

# Find by keyword
grep -rl "accuracy" references/
grep -rl "promotion" references/
grep -rl "ownership" references/
grep -rl "anti-pattern" references/

Problem to Reference Mapping

Problem	Start With
Annual review for 1 engineer	annual-review-process.md then report-templates.md
Comparing 2+ engineers for promotion	annual-review-process.md then qualitative-judgment.md
Engineer has 200+ commits	agent-context-management.md (read FIRST)
Session keeps running out of context	agent-context-management.md
Is this engineer ready for promotion?	qualitative-judgment.md then accuracy-analysis.md
Who owns the payment system?	production-ownership.md
Track progress since last review	historical-progress.md
Quality assessment from code	code-quality-catalog.md then accuracy-analysis.md
Single points of failure in team	production-ownership.md
Plateau detection	historical-progress.md

Full Compiled Document

For the complete guide with all references expanded: AGENTS.md

Usage Examples

# Annual review (single engineer)
Analyze @alice for 2025 annual review in repo org/repo.
Git email: [e-mail]. Write to ./alice-2025-review.md

# Multi-engineer comparison with promotion decision
Analyze @alice, @bob, @charlie for 2025 reviews.
I need to decide which 2 get promoted.

# Production ownership mapping
Analyze production code ownership in this repo.

# Incremental progress update
Update @alice's progress profile with latest contributions.

# Critical path risk detection
Find single points of failure in production code ownership.

# Plateau detection
Has @bob plateaued? Check last 3 quarters.