Event Store

Guide to designing event stores for event-sourced applications — covering event schemas, projections, snapshotting, and CQRS integration.

What's Inside

• Event Store Architecture — streams, global position, requirements
• Technology Comparison — EventStoreDB, PostgreSQL, Kafka, DynamoDB
• Event Schema Design — envelope structure, schema evolution rules
• PostgreSQL Event Store Schema — events, snapshots, subscription checkpoints
• Event Store Implementation — append with optimistic concurrency, read stream, read all (Python)
• Projections — lifecycle, idempotent handlers, design rules, projection example
• Snapshotting — snapshot flow, aggregate rehydration optimization
• CQRS Integration — write/read separation, command handler pattern
• EventStoreDB Integration example (Python)
• DynamoDB Event Store Implementation with single-table design

When to Use

• Designing event sourcing infrastructure
• Choosing between event store technologies
• Implementing custom event stores
• Building projections from event streams
• Adding snapshotting for aggregate performance
• Integrating CQRS with event sourcing

Installation

npx add https://github.com/wpank/ai/tree/main/skills/backend/event-store

Manual Installation

Cursor (per-project)

From your project root:

mkdir -p .cursor/skills
cp -r ~/.ai-skills/skills/backend/event-store .cursor/skills/event-store

Cursor (global)

mkdir -p ~/.cursor/skills
cp -r ~/.ai-skills/skills/backend/event-store ~/.cursor/skills/event-store

Claude Code (per-project)

From your project root:

mkdir -p .claude/skills
cp -r ~/.ai-skills/skills/backend/event-store .claude/skills/event-store

Claude Code (global)

mkdir -p ~/.claude/skills
cp -r ~/.ai-skills/skills/backend/event-store ~/.claude/skills/event-store

Related Skills

• architecture-patterns — Clean Architecture and DDD foundations for event sourcing
• microservices-patterns — Saga pattern and distributed transactions with events

Part of the Backend skill category.