2.4. Performance Optimization

💡 First Principle: A system that works is not necessarily a system that performs well. Think of it like a car engine: it can run without being tuned, but without optimization it consumes more fuel, runs hotter, and degrades faster. Consider this: what happens when an EC2 instance type was chosen two years ago and the workload has since changed? Performance optimization is the practice of ensuring resources match actual demand — unlike static provisioning that made sense at launch but wastes money or causes bottlenecks at scale. Performance optimization is the discipline of matching resource configuration to workload requirements — using exactly the right amount and type of resource for the task, no more and no less.

This section covers what was formerly Domain 6 in SOA-C02 (Cost and Performance Optimization), now merged into Domain 1. Expect 4–6 questions across compute, storage, and database performance. The exam tests your ability to select the right service or configuration for a described workload, not just name the options.