Integration Best Practices

Performance Optimization

1. Use Batch Operations

2. Implement Pagination

• Don't fetch 100K records at once (timeout, memory issues)
• Use PageSize=50, PageNumber=1 parameters
• Iterate through pages: Page 1 → Page 2 → ... → Page N

3. Delta Sync (Not Full Sync)

• Track last sync timestamp: LastSync = 2024-01-15 10:00 AM
• Query only changed records: WHERE ModifiedDate > '2024-01-15 10:00'
• Example: Sync 100 changed accounts (not all 100K accounts)

4. Async for Non-Critical Operations

• Sync (wait): Payment processing, inventory checks
• Async (fire-and-forget): Email notifications, audit logs, analytics updates

Error Handling & Resilience

1. Retry Logic

2. Circuit Breaker

• If external system fails 10 times in 5 min → Stop calling it (circuit "open")
• Wait 5 min, then try 1 test call → If success, resume normal calls (circuit "closed")
• Benefit: Prevents cascading failures, gives failing system time to recover

3. Graceful Degradation

• Scenario: Inventory API is down
• Bad: Block entire order creation (user can't proceed)
• Good: Create order with status "Pending Inventory Validation", check later when API recovers

4. Comprehensive Logging

• Log every integration call: Timestamp, endpoint, payload, response, duration
• Example Log: 2024-01-15 14:32:15 | POST /api/orders | Payload: {...} | Response: 500 Error | Duration: 3.2s
• Use correlation IDs to trace requests across systems

Security Best Practices

1. Never Hardcode Credentials

• Bad: password = "MyP@ssw0rd" in source code
• Good: Store in encrypted config file or vault (HashiCorp Vault, Azure Key Vault)

2. Use OAuth 2.0 (Not Basic Auth)

• OAuth tokens expire (1 hour), can be revoked
• Basic auth credentials don't expire, harder to rotate

3. Encrypt Data in Transit

• Always use HTTPS (not HTTP)
• TLS 1.2 or higher
• Reject self-signed certificates in production

4. Input Validation

• Validate all incoming data (check data types, length, format)
• Sanitize inputs to prevent SQL injection, XSS attacks
• Example: Email field must match /^[^@]+@[^@]+$/

5. Rate Limiting

• Limit API calls: 1,000 requests/hour per client
• Prevents abuse, DoS attacks

Data Quality & Consistency

1. Idempotency

2. Data Mapping Standards

• Document field mappings: Siebel.Account.Name → SAP.Customer.Name
• Use common data formats: ISO dates (YYYY-MM-DD), E.164 phone numbers (+1-555-123-4567)
• Handle nulls: Agree on how to represent "no value" (null, empty string, "N/A"?)

3. Master Data Management

• Designate "system of record" for each data type
• Example: ERP = master for products, Siebel = master for contacts
• One-way sync from master → Other systems (avoid circular updates)

Monitoring & Observability

• Health Checks: Ping integration endpoints every 5 min (alert if down)
• Performance Metrics: Track average response time, error rate, throughput
• Alerts: Email/Slack notification if error rate > 5% or response time > 10s
• Dashboards: Real-time view of integration health (Grafana, Datadog)

Testing Strategies

1. Unit Tests

• Test individual functions (e.g., data transformation logic)
• Mock external API calls

2. Integration Tests

• Test end-to-end flow in sandbox environment
• Example: Create account in Siebel → Verify it appears in ERP within 5 min

3. Load Testing

• Simulate high volume: 10,000 API calls in 1 hour
• Identify bottlenecks, optimize before production

4. Chaos Engineering

• Deliberately break things to test resilience
• Example: Disable ERP → Verify circuit breaker activates, Siebel degrades gracefully

Documentation

Summary: Integration Checklist