The Challenge
A fast-growing Dutch e-commerce platform needed to prepare for Black Friday - their biggest sales event of the year. Previous years resulted in website slowdowns and lost revenue due to infrastructure limitations.
Requirements
- Handle 10x traffic spike (100K → 1M concurrent users)
- Maintain performance (<1s page load times)
- Zero downtime during peak hours
- Cost-effective - No over-provisioning
- 2-week timeline before Black Friday
Our Solution
Week 1: Assessment & Architecture
Performance Testing:
- Load tested current infrastructure
- Identified bottlenecks (database, caching, static assets)
- Created capacity planning model
Architecture Design:
- CloudFront CDN for static assets and caching
- Auto-scaling for EC2 instances
- RDS Read Replicas for database scaling
- ElastiCache for session management
- S3 for product images and media
Week 2: Implementation & Testing
Infrastructure Deployment:
- Migrated static assets to S3 + CloudFront
- Implemented Redis caching with ElastiCache
- Set up auto-scaling policies
- Created RDS read replicas
- Configured CloudWatch alarms
Load Testing:
- Simulated 1.5M concurrent users
- Tested auto-scaling triggers
- Validated cache hit rates (>90%)
- Confirmed database performance
Black Friday Results
Traffic Handled
- Peak: 1.2M concurrent users
- Page views: 50M+ in 24 hours
- Transactions: 500K+ orders processed
- Uptime: 100% availability
Performance Metrics
- Page load: 0.8s average (vs 3.5s previous year)
- API response: <100ms (vs 800ms previous year)
- Cache hit rate: 94%
- Error rate: 0.001% (vs 5% previous year)
Business Impact
- €2M+ sales during peak hours
- Customer satisfaction increased by 35%
- Cart abandonment reduced from 45% to 22%
- Infrastructure costs 80% lower than pre-provisioning would have been
Auto-scaling in Action
- Started with: 5 EC2 instances
- Scaled to: 50 instances during peak
- Scaled down to: 8 instances post-event
- Cost savings: Only paid for what was used
Architecture Highlights
Content Delivery
User → CloudFront (CDN)
→ S3 (Static Assets)
→ ALB → EC2 Auto-scaling Group
→ ElastiCache (Sessions)
→ RDS (Primary + 3 Read Replicas)Caching Strategy
- CloudFront: Product pages, images, CSS/JS (24hr TTL)
- ElastiCache: Sessions, cart data, frequently accessed products
- Application-level: Database query results
- Result: 94% cache hit rate, massive DB load reduction
Monitoring
- Real-time CloudWatch dashboards
- Auto-scaling based on CPU, memory, request count
- Alerts for error rates, latency spikes
- Business metrics (orders/minute, revenue)
Client Testimonial
“Last year, our site crashed during Black Friday and we lost hundreds of thousands in sales. This year, with Forrict’s help, we handled 10x the traffic flawlessly. The auto-scaling worked perfectly - we only paid for what we needed, when we needed it.”
— CTO, Dutch Online Retailer
Key Success Factors
- CDN First - Offloading 80% of requests to CloudFront was game-changing
- Aggressive Caching - 94% cache hit rate reduced database load dramatically
- Auto-scaling - Automatically handled traffic spikes without intervention
- Load Testing - Testing at 150% expected capacity gave confidence
- Monitoring - Real-time dashboards enabled proactive response
Technologies Used
AWS Services: CloudFront, S3, EC2, Auto Scaling, RDS, ElastiCache, CloudWatch, ALB Stack: Node.js, Redis, PostgreSQL Tools: Apache JMeter (load testing), Datadog (monitoring)
Post-Event Optimization
After Black Friday, we helped optimize for ongoing operations:
- Fine-tuned auto-scaling policies
- Implemented cost optimization (Reserved Instances, Spot Instances)
- Set up automated backup and disaster recovery
- Created runbooks for future peak events
Preparing for your next big sales event? Let’s ensure your success