copilot-instructions: Instructions file for GitHub Copilot

Service boundaries

• Single responsibility
• Domain-driven boundaries
• Database per service
• Prefer async communication
• Event-driven architecture
• Saga for distributed transactions
• API gateway as entry point

routes:
  - path: /orders
    service: order-service

Performance

• Configured connection pooling
• Consistent async/await
• Bulk operations
• Appropriate lazy loading
• Distributed cache (Redis)
• CDN for assets
• Compression enabled

var cache = ConnectionMultiplexer.Connect("redis");
cache.GetDatabase().StringSet("key", value);

Resource efficiency

• Minimal images
• Multi-stage builds
• Defined resource limits
• Accurate CPU/memory requests
• HPA/VPA
• Tuned probes

resources:
  limits:
    cpu: "500m"
    memory: "512Mi"
  requests:
    cpu: "250m"
    memory: "256Mi"

Communication

• gRPC for service-to-service
• REST for external APIs
• Message queues for async
• Circuit breaker
• Retries with exponential backoff
• Timeouts
• Idempotent operations

.AddPolicyHandler(Policy.Handle<Exception>().WaitAndRetryAsync(3, retry => TimeSpan.FromSeconds(Math.Pow(2, retry))))

Consistency

• Eventual consistency by default
• CQRS when applicable
• Event sourcing for audit
• Saga orchestration
• Compensation patterns
• Avoid distributed transactions
• Optimized read models

public class OrderSaga { /* Orchestrate steps with compensation */ }

Caching

• Application cache
• Distributed cache
• Cache-aside
• Write-through when needed
• Proper TTL
• Invalidation
• Warming
• Hierarchy

var value = cache.Get("key") ?? LoadAndCache("key");

Load balancing

• Round-robin default
• Health-based routing
• Session affinity when needed
• Geo routing
• A/B testing
• Canary
• Blue-green

spec:
  template:
    metadata:
      labels:
        version: v2
  traffic: 10%

Monitoring

• Structured logs
• Correlation IDs
• Metrics aggregation
• Tracing
• SLA monitoring
• Error rate
• Latency percentiles
• Resource utilization

- job_name: 'service'
  metrics_path: /metrics