---
name: event-sourcing-migrator-90cdbeb7bef8
description: Migrate to event-sourcing architecture with event extraction, store setup, and CQRS implementation
allowed-tools: ["Bash", "Read", "Write", "Grep", "Glob", "Edit"]
graph:
  domains: [domain:software-engineering]
  specializations: [specialization:code-migration-modernization]
  skillAreas: [skill-area:event-sourcing, skill-area:cqrs]
  roles: [role:architect, role:backend-engineer]
  workflows: [workflow:technical-debt-reduction]
  topics: [topic:refactoring]
---

# Event Sourcing Migrator Skill

Migrates applications to event-sourcing architecture, handling event extraction from existing data, event store setup, and CQRS implementation.

## Purpose

Enable event sourcing migration for:
- Event extraction from existing data
- Event store setup
- Projection generation
- CQRS implementation
- Snapshot management

## Capabilities

### 1. Event Extraction from Existing Data
- Analyze current state
- Derive historical events
- Generate event streams
- Handle data gaps

### 2. Event Store Setup
- Configure event store
- Set up partitioning
- Define retention
- Implement subscriptions

### 3. Projection Generation
- Create read models
- Build projections
- Handle updates
- Manage consistency

### 4. CQRS Implementation
- Separate read/write
- Implement commands
- Handle queries
- Manage eventual consistency

### 5. Snapshot Management
- Define snapshot strategy
- Generate snapshots
- Handle restoration
- Optimize performance

### 6. Event Replay
- Replay events
- Rebuild projections
- Handle migrations
- Test consistency

## Tool Integrations

| Tool | Purpose | Integration Method |
|------|---------|-------------------|
| EventStore | Event database | CLI/API |
| Axon Framework | Java event sourcing | Library |
| Marten | .NET event store | Library |
| EventStoreDB | Event store | CLI |
| Custom stores | PostgreSQL/Kafka | Library |

## Output Schema

```json
{
  "migrationId": "string",
  "timestamp": "ISO8601",
  "eventStore": {
    "type": "string",
    "streams": "number",
    "events": "number"
  },
  "projections": [
    {
      "name": "string",
      "status": "string",
      "lastPosition": "number"
    }
  ],
  "snapshots": {
    "enabled": "boolean",
    "count": "number"
  }
}
```

## Integration with Migration Processes

- **monolith-to-microservices**: Event-driven architecture
- **database-schema-migration**: Data transformation

## Related Skills

- `domain-model-extractor`: Event discovery

## Related Agents

- `data-architect-agent`: Event architecture


---
Source attribution: a5c-ai
Original project: https://github.com/a5c-ai/babysitter
License: MIT
License information: https://opensource.org/license/mit
Original upstream instructions; downloaded from Mega AI Hub.

## Upstream license notice

MIT License

Copyright (c) 2026 Gabriel Moreira

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.



# Mega AI Hub resource metadata

Creator / publisher: a5c-ai
Original project: https://github.com/a5c-ai/babysitter
Attribution basis: Upstream repository explicitly recorded in package mirror path

Fields of work: Development & Engineering, Product Management
Roles: Backend Developer, Data Engineer, DevOps / SRE, Product Manager, Technical Product Manager
Specialties: API, Backend
Tools: Eventstore, Eventstoredb, Kafka, Marten, Postgresql, Axon Framework
Country applicability: Country not specified
Classification basis: Source catalog labels
Instruction SHA-256: f01596e6b27d41196c94fc14f690d84adb770157d02c80e1cce78e53db1d4674