#Capacity Planning & Scaling Document

#Current State Assessment

#System Metrics (as of [Date])

• Current daily active users
• Peak requests per second (RPS)
• Average response time (p50/p95/p99)
• Error rate
• Data storage used
• Resource utilization (CPU, memory, disk)

#Infrastructure Details

• Number of application servers
• Database configuration (replicas, shards, etc.)
• Cache configuration
• CDN/load balancer setup
• Region/availability zone setup

#Growth Projections

#Forecasted Growth

• User growth rate
• Expected peak RPS in 3/6/12 months
• Data growth projections
• Usage pattern changes expected

#Traffic Patterns

• Daily peaks and troughs
• Seasonal variations
• Special events that cause spikes

#Scaling Limits

#Current Bottlenecks

• What limits us today?
  • Database connection pool
  • Memory constraints
  • I/O limitations
  • External service rate limits
  • Network bandwidth

#Projected Capacity Headroom

• How long until we hit limits (in months)?
• When do we need to take action?
• Action items and timeline

#Scaling Strategies

#Horizontal Scaling

Application Layer:

• Load balancing strategy
• Session management approach
• Stateless design requirements
• Max number of instances

Database Layer:

• Replication approach
• Read replicas strategy
• Sharding approach (if needed)
• Consistency model

Cache Layer:

• Cache distribution strategy
• Eviction policy
• Warming strategy

#Vertical Scaling

• Current instance size
• Available larger instances
• When horizontal scaling isn't enough
• Cost implications

#Feature-Level Scaling

• Feature flags for traffic shaping
• Graceful degradation strategies
• Circuit breakers
• Rate limiting approach

#Infrastructure Upgrades

#Immediate (0-3 months)

#Medium-term (3-6 months)

#Long-term (6-12 months)

#Performance Optimization Opportunities

• Low-hanging fruit for improvement
• Estimated impact of each optimization
• Timeline for implementation

#Cost Implications

• Current monthly infrastructure cost
• Projected cost increase with growth
• Cost optimization strategies
• ROI of scaling investments

#Testing & Validation

#Load Testing Plan

• How to simulate projected load
• Testing methodology
• Key metrics to measure
• Acceptable failure modes

#Staging Validation

• How to test scaling procedures in staging
• Frequency of capacity tests
• Rollback procedures

#Monitoring & Alarms

#Early Warning Indicators

• Metrics that signal capacity issues
• Alert thresholds
• Action triggers

#Post-Scaling Validation

• Metrics to verify scaling was successful
• Dashboard updates needed
• Communication to stakeholders

#Owner & Review

• Owner: [Team/Person]
• Last reviewed: [Date]
• Next review: [Date]
• Previous versions/history: [Links]