How I Saved a Client ₹85,000/Month on AI API Costs — A Practical Breakdown

Originally shared on LinkedIn where it reached 10,000+ professionals. Expanded with technical details and actionable strategies here. A client was burning through ₹85,000/month on AI API calls. In one weekend, we cut that to under ₹12,000 . I'm not exaggerating. This is real money saved by a real company that had no idea they were hemorrhaging cash on AI infrastructure. The worst part? They thought that's just "the cost of doing AI." It's not. If you're using AI APIs in production—Claude, GPT-4, Gemini, whatever—there's a 90% chance you're overspending. This article walks through exactly how we diagnosed the problem and fixed it. The Problem: Why Your AI Bill Looks Like a Mortgage Payment Before the audit, here's what the client was doing: Using Opus (₹15/1M tokens) for simple tasks — asking GPT-4-level models to classify customer emails or generate summaries when Haiku (₹0.80/1M tokens) would work fine. Zero prompt caching — sending the same 50KB system prompt with every API call. Tha