// 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.
Conduct WCAG 2.2 accessibility audits with automated testing, manual verification, and remediation guidance. Use when auditing websites for accessibility, fixing WCAG violations, or implementing accessible design patterns.
Create production-ready FastAPI projects with async patterns, dependency injection, and comprehensive error handling. Use when building new FastAPI applications or setting up backend API projects.
Master REST and GraphQL API design principles to build intuitive, scalable, and maintainable APIs that delight developers. Use when designing new APIs, reviewing API specifications, or establishing API design standards.
Implement proven backend architecture patterns including Clean Architecture, Hexagonal Architecture, and Domain-Driven Design. Use this skill when designing clean architecture for a new microservice, when refactoring a monolith to use bounded contexts, when implementing hexagonal or onion architecture patterns, or when debugging dependency cycles between application layers.
Implement Command Query Responsibility Segregation for scalable architectures. Use when separating read and write models, optimizing query performance, or building event-sourced systems.
Design and implement event stores for event-sourced systems. Use when building event sourcing infrastructure, choosing event store technologies, or implementing event persistence patterns.
| name | projection-patterns |
| description | 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. |
Comprehensive guide to building projections and read models for event-sourced systems.
┌─────────────┐ ┌─────────────┐ ┌─────────────┐
│ 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 |
Full template library and detailed worked examples live in references/details.md. Read that file when you need the concrete templates.