Service Layer Architecture

Controller-service-query layered API architecture with data enrichment and parallel fetching. Use when building REST APIs or GraphQL resolvers with clean separation of concerns.

What's Inside

• Three-Layer Architecture — controllers (HTTP handling), services (business logic), queries (database access)
• Layer 1: Controllers — HTTP-only concerns, request parsing, validation, status codes
• Layer 2: Services — business logic, data enrichment, parallel data fetching with Promise.all
• Layer 3: Queries — database access, raw data retrieval with .lean()
• Parallel Data Fetching — sequential vs parallel comparison
• Layer Responsibilities table — clear ownership of each concern

When to Use

• Building REST APIs with complex data aggregation
• GraphQL resolvers needing data from multiple sources
• Any API where responses combine data from multiple queries
• Systems needing testable, maintainable code

Installation

npx add https://github.com/wpank/ai/tree/main/skills/backend/service-layer-architecture

Manual Installation

Cursor (per-project)

From your project root:

mkdir -p .cursor/skills
cp -r ~/.ai-skills/skills/backend/service-layer-architecture .cursor/skills/service-layer-architecture

Cursor (global)

mkdir -p ~/.cursor/skills
cp -r ~/.ai-skills/skills/backend/service-layer-architecture ~/.cursor/skills/service-layer-architecture

Claude Code (per-project)

From your project root:

mkdir -p .claude/skills
cp -r ~/.ai-skills/skills/backend/service-layer-architecture .claude/skills/service-layer-architecture

Claude Code (global)

mkdir -p ~/.claude/skills
cp -r ~/.ai-skills/skills/backend/service-layer-architecture ~/.claude/skills/service-layer-architecture

Related Skills

• postgres-job-queue — Background job processing
• architecture-patterns — Clean Architecture, Hexagonal, and DDD patterns

Part of the Backend skill category.