Custom Knowledge

# Payment Service

## Overview
Handles all financial transactions for checkout and subscriptions.
Critical path: API Gateway → Payment Lambda → Stripe API → DynamoDB

## Dependencies
- Stripe API (external) - payment processing
- DynamoDB table: payments-prod - transaction records
- SQS queue: payment-events - async processing
- Redis cluster: payment-cache - rate limiting

## On-Call Contacts
- Primary: @payments-team in Slack
- Escalation: [email protected]

## Common Issues
1. Stripe timeouts: Check Stripe status page first
2. DynamoDB throttling: Scale up RCU or check for hot partitions
3. Lambda cold starts: Check concurrent execution limits

## Key Dashboards
- Datadog: "Payment Service Overview"
- CloudWatch alarm: payment-lambda-errors
- Business metric: checkout_success_rate

# Authentication Service

## Overview
Handles user login, SSO, and session management.
Critical for all user-facing applications.

## Dependencies
- Auth0 (external) - identity provider
- Redis cluster: session-cache - session storage
- PostgreSQL: users-db - user profiles
- Kafka: auth-events - audit logging

## On-Call Contacts
- Primary: @platform-team in Slack
- Security issues: [email protected] (immediate escalation)

## Common Issues
1. Auth0 rate limits: Check Auth0 dashboard, may need to request limit increase
2. Session cache misses: Usually Redis memory pressure, check eviction rate
3. Login failures spike: Often caused by downstream service issues, not auth itself

## Key Dashboards
- Datadog: "Auth Service Health"
- Auth0 Dashboard: https://manage.auth0.com/
- Metric to watch: login_success_rate (alert if < 99%)

# Database Operations

## Production Databases
| Database | Type | Primary Use | Owner |
|----------|------|-------------|-------|
| users-db | PostgreSQL | User profiles | @platform-team |
| orders-db | PostgreSQL | Order history | @commerce-team |
| analytics-db | ClickHouse | Reporting | @data-team |

## Connection Strings
- Production: Use AWS Secrets Manager, secret name: prod/db/credentials
- Staging: Use AWS Secrets Manager, secret name: staging/db/credentials

## Common Issues
1. Connection pool exhaustion: Check active connections in RDS console
   - Normal: < 80% of max_connections
   - Alert: > 90% of max_connections
   
2. Slow queries: Check pg_stat_statements for queries > 1s
   - Runbook: https://wiki.company.com/db-slow-queries

3. Replication lag: Check CloudWatch ReplicaLag metric
   - Normal: < 100ms
   - Alert: > 1s

## Maintenance Windows
- Production: Sundays 2-4 AM UTC
- Staging: No restrictions

# Naming Conventions

## Resource Naming Pattern
{env}-{service}-{resource-type}-{identifier}

Examples:
- prod-payment-lambda-processor
- staging-auth-rds-primary
- dev-api-ec2-worker-01

## Environments
- prod: Production (us-east-1, eu-west-1)
- staging: Pre-production testing (us-east-1)
- dev: Development (us-west-2)

## Tagging Standards
All resources MUST have:
- Environment: prod | staging | dev
- Service: service name (e.g., payment, auth, api)
- Owner: team email (e.g., [email protected])
- CostCenter: finance code (e.g., CC-1234)

## Terraform Module Locations
- Infrastructure: github.com/company/terraform-infra
- Modules: github.com/company/terraform-modules
- Environments: github.com/company/terraform-envs/{env}

# Incident Response

## Severity Levels
- SEV1: Customer-facing outage, all hands on deck
- SEV2: Degraded service, on-call + team lead
- SEV3: Minor issue, on-call only

## Escalation Path
1. On-call engineer (PagerDuty)
2. Team lead (after 15 min for SEV1/SEV2)
3. Engineering manager (after 30 min for SEV1)
4. VP Engineering (after 1 hour for SEV1)

## Communication Channels
- Incidents: #incidents (Slack)
- War room: #incident-{id} (created automatically)
- Status page: https://status.company.com

## Post-Incident
- Blameless postmortem within 48h for SEV1/SEV2
- Template: https://wiki.company.com/postmortem-template
- Review meeting: Thursdays 2 PM

## Key Contacts
- On-call: Check PagerDuty schedule
- Security: [email protected]
- Legal (data breach): [email protected]