Backend Development

Skill 16 of 183

Projection Patterns

Build read models and projections from event streams. Use when implementing CQRS read sides, building materialized views, or optimizing query performance in event-sourced systems.

1 minute · 171 words · 8 sections

Install

$ npx skills add wshobson/agents --skill projection-patterns

$ npx skills add wshobson/agents

» /plugin marketplace add wshobson/agents

The first command installs just this skill, by the name in its SKILL.md; the second installs the whole repository.

Comprehensive guide to building projections and read models for event-sourced systems.

When to Use This Skill

Building CQRS read models
Creating materialized views from events

Projection Patterns · wshobson/agents · Skills Docs

┌─────────────┐     ┌─────────────┐     ┌─────────────┐
│ Event Store │────►│ Projector   │────►│ Read Model  │
│             │     │             │     │ (Database)  │
│ ┌─────────┐ │     │ ┌─────────┐ │     │ ┌─────────┐ │
│ │ Events  │ │     │ │ Handler │ │     │ │ Tables  │ │
│ └─────────┘ │     │ │ Logic   │ │     │ │ Views   │ │
│             │     │ └─────────┘ │     │ │ Cache   │ │
└─────────────┘     └─────────────┘     └─────────────┘

Type	Description	Use Case
Live	Real-time from subscription	Current state queries
Catchup	Process historical events	Rebuilding read models
Persistent	Stores checkpoint	Resume after restart
Inline	Same transaction as write	Strong consistency

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How this issue was made

Source

github.com/wshobson/agents, branch main, last pushed 21 September 2026.

Licence

MIT — the text of every skill is reproduced unmodified, frontmatter included, under the upstream licence.

Discovery

183 skills found by walking the repository tree for SKILL.md, not by matching a directory convention. 51 distinct layouts observed: plugins/accessibility-compliance/skills/*/SKILL.md, plugins/agent-teams/skills/*/SKILL.md, plugins/api-scaffolding/skills/*/SKILL.md, plugins/avoid-ai-writing/skills/*/SKILL.md, plugins/backend-development/skills/*/SKILL.md, plugins/before-you-build/skills/*/SKILL.md, plugins/block-no-verify/skills/*/SKILL.md, plugins/blockchain-web3/skills/*/SKILL.md, plugins/brand-landingpage/skills/*/SKILL.md, plugins/business-analytics/skills/*/SKILL.md, plugins/cicd-automation/skills/*/SKILL.md, plugins/cloud-infrastructure/skills/*/SKILL.md, plugins/conductor/skills/*/SKILL.md, plugins/data-engineering/skills/*/SKILL.md, plugins/database-design/skills/*/SKILL.md, plugins/developer-essentials/skills/*/SKILL.md, plugins/dgx-spark-ops/skills/*/SKILL.md, plugins/documentation-generation/skills/*/SKILL.md, plugins/documentation-standards/skills/*/SKILL.md, plugins/dotnet-contribution/skills/*/SKILL.md, plugins/file-conversion/skills/*/SKILL.md, plugins/framework-migration/skills/*/SKILL.md, plugins/frontend-mobile-development/skills/*/SKILL.md, plugins/game-development/skills/*/SKILL.md, plugins/hermes-tweet/skills/*/SKILL.md, plugins/hr-legal-compliance/skills/*/SKILL.md, plugins/incident-response/skills/*/SKILL.md, plugins/javascript-typescript/skills/*/SKILL.md, plugins/kubernetes-operations/skills/*/SKILL.md, plugins/llm-application-dev/skills/*/SKILL.md, plugins/llm-finetuning/skills/*/SKILL.md, plugins/machine-learning-ops/skills/*/SKILL.md, plugins/observability-monitoring/skills/*/SKILL.md, plugins/payment-processing/skills/*/SKILL.md, plugins/plugin-eval/skills/*/SKILL.md, plugins/pptx-deck-creation/skills/*/SKILL.md, plugins/protect-mcp/skills/*/SKILL.md, plugins/python-development/skills/*/SKILL.md, plugins/quantitative-trading/skills/*/SKILL.md, plugins/reverse-engineering/skills/*/SKILL.md, plugins/review-agent-governance/skills/*/SKILL.md, plugins/security-scanning/skills/*/SKILL.md, plugins/shell-scripting/skills/*/SKILL.md, plugins/ship-mate/skills/*/SKILL.md, plugins/signed-audit-trails/skills/*/SKILL.md, plugins/skill-forge-essentials/skills/*/SKILL.md, plugins/social-publishing/skills/*/SKILL.md, plugins/startup-business-analyst/skills/*/SKILL.md, plugins/superself/skills/*/SKILL.md, plugins/systems-programming/skills/*/SKILL.md, plugins/ui-design/skills/*/SKILL.md.

Issue colours

Resolved from a deterministic hash of the owner name. Two accent tones are generated per issue and each is proven against its own ground before it ships: a single accent that passes AA on both light and dark paper is arithmetically impossible.

Heading repairs

1 repair applied to this skill so the document has one h1 and no skipped levels:

Removed “Projection Patterns”, a leading h1 that duplicated the skill title.

Spec compliance

Every skill satisfies the Agent Skills specification’s frontmatter rules.

Images

Images inside a skill come from the upstream repository. Where the author gave no alternative text we mark the image decorative rather than inventing a description — a plausible caption we made up is worse than none for the reader who depends on it.

Marketplace

A plugin manifest is published at .claude-plugin/marketplace.json by Seth Hobson, declaring 94 plugins. It is read for editorial metadata only — never as the skill index, which is always the repository tree.

Signal

Install counts come from skills.sh. They measure downloads, not quality, and an unranked repository is not an unread one.

Agent surfaces

The whole issue is available as one markdown document at /wshobson/agents.md, and each skill at its own .md URL.

Publication

Set by Skills Docs from the source repository. Body text is Literata at the reader’s chosen size and measure; code is Geist Mono. Nothing on this page was written by us except this paragraph.

Projection Patterns

When to Use This Skill

Projection Patterns

When to Use This Skill

Core Concepts

1. Projection Architecture

2. Projection Types

Templates and detailed worked examples

Best Practices

Do’s

Don’ts

Appendix 16.1

ReferencesMarkdown · 1 file

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Appendix 16.1

ReferencesMarkdown · 1 file