Developer Cuts AI API Costs by 61% Using Model Routing and Fallback Logic

A developer building an AI-powered app was spending $800 per month on OpenAI API calls despite having fewer than 500 active users. After auditing a week of LLM calls, they found that 62% of requests involved simple tasks like classification that did not require expensive flagship models. They implemented task-based model routing, directing simpler workloads to cheaper models such as GPT-4o-mini or Claude Haiku, which cost roughly 10 times less per token. A fallback layer was added to handle provider outages, and an API gateway was adopted to centralize routing, key management, and retry logic. Within three weeks, monthly costs fell by 61% while reliability improved and the codebase became simpler to maintain.