10 AWS Cost Optimization Mistakes I See in Real Accounts

AWS is powerful. Flexible. Scalable. It is also very good at quietly draining money if you’re not paying attention. After reviewing dozens of real AWS accounts—startups burning runway, scale-ups growing fast, and enterprises with seven-figure bills—these are the same cost mistakes I see again and again . This is not theory. This is what actually shows up in production accounts. And no, this isn’t about being cheap. It’s about spending with intent instead of fear . 1. Overprovisioned EC2 Instances (Everyone Does This) What I usually find: m5.4xlarge instances barely breaking 5–10% CPU Memory usage chilling below 30% No one has looked at metrics in months Why it happens: “What if traffic spikes?” “Let’s be safe” Lift-and-shift migrations where nothing got revisited What actually works: Turn on Compute Optimizer Look at CloudWatch metrics (CPU, memory, network) Downsize first, then scale only if you actually need to 💡 Just right-sizing EC2 often cuts costs by 30–60% with zero user impact.