How I Cut Our AI API Bill by 95% — The Engineering Playbook
When our finance lead forwarded me the AWS bill for March, I almost choked on my coffee. We were a team of nine engineers shipping AI features, and somehow we'd burned through enough on inference to cover two salaries. The worst part? I hadn't even noticed because the charges were scattered across OpenAI, Anthropic, and a couple of side experiments. That's the moment I decided to actually treat LLM spending like a real infrastructure problem instead of a credit card swipe.
What follows is the playbook I wish I'd had on day one. These aren't theoretical tips — they're the exact moves I made across three products to get our run-rate down to roughly 5% of where it started, without shipping worse software.
The Harsh Truth About Model Defaults
Here's the dirty secret nobody tells you in the LLM hype cycle: most teams default to the most famous model for every single call. GPT-4o for everything. Claude Sonnet for everything. Then they wonder why their "simple AI feature" costs them a kidney.
