Dev Environment Cost Optimization Plan

Your Savings Analysis

Current Setup:

• 2 EC2 instances running 24/7
• Work schedule: 9am-5pm EST, Monday-Friday
• Assumed instance type: t3.medium (common dev instance)

Cost Breakdown:

Current Monthly Cost (24/7):
- 2x t3.medium @ $0.0416/hour
- 2 x $0.0416/hr x 730 hrs/month = $60.74/month
- Annual: $728.88/year

Hours Analysis:

Total hours per month:        730 hours (24/7)
Work hours per month:         173 hours (8 hrs/day x 21.6 work days)
Idle hours per month:         557 hours (76.3%)

Projected Savings

Monthly Savings:              $46.07
Annual Savings:               $552.84
Savings Percentage:           76.3%
ROI Timeline:                 Immediate

Implementation Scripts

Option A: AWS Instance Scheduler (Recommended)

Step 1: Deploy via CloudFormation

• Go to AWS Console -> CloudFormation -> Create Stack
• Use AWS Solutions Library template for Instance Scheduler

Step 2: Create Schedule in DynamoDB

# Create period definition (9am-5pm weekdays)
aws dynamodb put-item \
  --table-name InstanceScheduler-ConfigTable-xxxxx \
  --item '{
    "type": {"S": "period"},
    "name": {"S": "work-hours"},
    "begintime": {"S": "09:00"},
    "endtime": {"S": "17:00"},
    "weekdays": {"SS": ["mon", "tue", "wed", "thu", "fri"]}
  }'

# Create schedule
aws dynamodb put-item \
  --table-name InstanceScheduler-ConfigTable-xxxxx \
  --item '{
    "type": {"S": "schedule"},
    "name": {"S": "dev-work-schedule"},
    "periods": {"SS": ["work-hours"]},
    "timezone": {"S": "America/New_York"}
  }'

Step 3: Tag Your EC2 Instances

aws ec2 create-tags \
  --resources i-xxxxxxxxx i-yyyyyyyyy \
  --tags Key=Schedule,Value=dev-work-schedule

Option B: EventBridge + Lambda

# Start at 9am EST (2pm UTC) Monday-Friday
aws events put-rule \
  --name start-dev-instances \
  --schedule-expression "cron(0 14 ? * MON-FRI *)" \
  --description "Start dev instances at 9am EST"

# Stop at 5pm EST (10pm UTC) Monday-Friday
aws events put-rule \
  --name stop-dev-instances \
  --schedule-expression "cron(0 22 ? * MON-FRI *)" \
  --description "Stop dev instances at 5pm EST"

Testing Protocol

Week 1: Test with ONE instance

• Tag single instance, monitor for 5 days
• Verify start/stop times and application functionality

Week 2: Full rollout

• Add second instance
• Monitor daily

Rollback Procedure

# Remove schedule tags
aws ec2 delete-tags \
  --resources i-xxxxxxxxx i-yyyyyyyyy \
  --tags Key=Schedule

# Manually start if needed
aws ec2 start-instances --instance-ids i-xxxxxxxxx i-yyyyyyyyy

Summary

What You’re Getting:

• $46.07/month savings ($552.84/year)
• 76.3% reduction in dev environment costs
• 2-4 hours implementation time
• Safe, gradual rollout with full rollback capability

Next Action: Choose Option A or B, tag ONE instance today, and start saving immediately.