Prompt

Design GraphQL federation architecture.

<existing_services>
{list services with their data domains}
</existing_services>

<client_needs>
{describe frontend query requirements}
</client_needs>

<federation_requirements>
- Schema ownership: {how to divide}
- Performance needs: {latency targets}
- Versioning strategy: {requirements}
</federation_requirements>

Design federation:
1. Subgraph boundaries
2. Entity relationships
3. Gateway configuration
4. Schema composition
5. Error handling
6. Performance optimization

Handle N+1 queries and caching.