Scalability Test Planning and Execution
Issue #111: System Design Interview Roadmap - Section 4: Scalability
What We'll Build Today
By the end of this lesson, you'll have:
A complete scalability testing framework that handles 1000+ requests per second
Real-time monitoring dashboard showing CPU, memory, and performance metrics
Automated load testing with realistic user behavior patterns
Performance analysis tools that identify bottlenecks before they hit production
Enterprise-grade testing patterns used by Netflix and Discord
The Scale Paradox
Your payment system handles 1,000 transactions per second beautifully in testing. Deploy to production during Black Friday, and it crumbles at 1,200 TPS—not from the load itself, but from unexpected connection pool exhaustion in a third-party library you never suspected.
This disconnect between test performance and production reality represents the fundamental challenge of scalability testing. Unlike functional testing where outputs are predictable, scalability testing reveals emergent behaviors that only surface when multiple system components interact under sustained pressure.
