Can this skill help with data recovery or migration?

Yes, it provides logic for 'Catchup' and 'Persistent' projections, which allow you to process historical event logs to rebuild state or migrate data to new schemas.

What are projection patterns in event sourcing?

Projection patterns are structural methods used to transform a sequential stream of events into a specific state or data format, typically stored in a database optimized for querying.

When should I use the Projection Patterns skill?

Use this skill when you need to build the read side of a CQRS system, optimize query performance in event-sourced applications, or create search indexes from historical data.

Which databases are supported by these templates?

The skill includes templates adaptable for most storage engines, with specific examples provided for relational databases like PostgreSQL and search engines like Elasticsearch.

Event Stream Projection Patterns

Name: Event Stream Projection Patterns
Author: 3commas-io

by3commas-io

データベース管理

Builds high-performance read models and materialized views from event streams for event-sourced systems.

概要

This skill provides specialized guidance and implementation patterns for building the read side of CQRS (Command Query Responsibility Segregation) architectures. It equips Claude with the architectural knowledge and code templates needed to transform raw event streams into optimized database tables, Elasticsearch indexes, and real-time dashboards. Whether you are implementing persistent checkpoints, handling historical catch-ups, or designing complex multi-table aggregations, this skill ensures your read models remain consistent, scalable, and performant.

主な機能

Standardized templates for basic and advanced event projectors
Pre-built logic for data aggregation and search index synchronization
Support for Live, Catchup, Persistent, and Inline projection types
Robust checkpointing mechanisms to ensure resume capability after restarts
Implementation patterns for PostgreSQL (asyncpg) and Elasticsearch
0 GitHub stars

ユースケース

Building optimized read-side views for microservices using CQRS
Synchronizing search engines like Elasticsearch with event-sourced data
Generating real-time business metrics and reporting dashboards from event streams

概要

主な機能

Standardized templates for basic and advanced event projectors
Pre-built logic for data aggregation and search index synchronization
Support for Live, Catchup, Persistent, and Inline projection types
Robust checkpointing mechanisms to ensure resume capability after restarts
Implementation patterns for PostgreSQL (asyncpg) and Elasticsearch
0 GitHub stars

ユースケース

Building optimized read-side views for microservices using CQRS
Synchronizing search engines like Elasticsearch with event-sourced data
Generating real-time business metrics and reporting dashboards from event streams