5 Mistakes Every Developer Makes When Using LLM APIs for the First Time

You write a few lines of code. You call the API. It responds. Everything feels effortless. Then 48 hours later everything falls apart. Your app throws errors you cannot explain. Your token costs are out of control. And the model keeps returning outputs that break your application logic. This is not bad luck. This is the pattern. A 2025 Stack Overflow survey found that over 84% of developers are now using AI tools in their workflow. But the same report highlighted that most developers struggle with reliability, cost control and debugging when working with LLM APIs for the first time.