gitlore/docs/ideas/silos.md

Knowledge Silo Detection

• Command: lore silos [--min-changes <N>]
• Confidence: 87%
• Tier: 2
• Status: proposed
• Effort: medium — requires mr_file_changes population (Gate 4)

What

For each file path (or directory), count unique MR authors. Flag paths where only 1 person has ever authored changes (bus factor = 1). Aggregate by directory to show silo areas.

Why

Bus factor analysis is critical for team resilience. If only one person has ever touched the auth module, that's a risk. This uses data already ingested to surface knowledge concentration that's otherwise invisible.

Data Required

• mr_file_changes (new_path, merge_request_id) — needs Gate 4 ingestion
• merge_requests (author_username, state='merged')
• projects (path_with_namespace)

Implementation Sketch

-- Find directories with bus factor = 1
WITH file_authors AS (
    SELECT
        mfc.new_path,
        mr.author_username,
        p.path_with_namespace,
        mfc.project_id
    FROM mr_file_changes mfc
    JOIN merge_requests mr ON mfc.merge_request_id = mr.id
    JOIN projects p ON mfc.project_id = p.id
    WHERE mr.state = 'merged'
),
directory_authors AS (
    SELECT
        project_id,
        path_with_namespace,
        -- Extract directory: everything before last '/'
        CASE
            WHEN INSTR(new_path, '/') > 0
            THEN SUBSTR(new_path, 1, LENGTH(new_path) - LENGTH(REPLACE(RTRIM(new_path, REPLACE(new_path, '/', '')), '', '')))
            ELSE '.'
        END as directory,
        COUNT(DISTINCT author_username) as unique_authors,
        COUNT(*) as total_changes,
        GROUP_CONCAT(DISTINCT author_username) as authors
    FROM file_authors
    GROUP BY project_id, directory
)
SELECT * FROM directory_authors
WHERE unique_authors = 1
  AND total_changes >= ?1  -- min-changes threshold
ORDER BY total_changes DESC;

Human Output

Knowledge Silos (bus factor = 1, min 3 changes)

group/backend
  src/auth/         alice (8 changes)    HIGH RISK
  src/billing/      bob (5 changes)      HIGH RISK
  src/utils/cache/  charlie (3 changes)  MODERATE RISK

group/frontend
  src/admin/        dave (12 changes)    HIGH RISK

Downsides

• Historical authors may have left the team; needs recency weighting
• Requires mr_file_changes to be populated (Gate 4)
• Single-author directories may be intentional (ownership model)
• Directory aggregation heuristic is imperfect for deep nesting

Extensions

• lore silos --since 180d — only count recent activity
• lore silos --depth 2 — aggregate at directory depth N
• Combine with lore experts to show both silos and experts in one view
• Risk scoring: weight by directory size, change frequency, recency