Production

Introduction # In 2026, large language models are deeply embedded in production systems across every industry. From Claude 4 Opus to GPT-5 Turbo, from Gemini 2.5 Pro to DeepSeek-V4, developers have an unprecedented selection of models at their fingertips. But calling these AI APIs in production is nothing like a quick notebook experiment. This article distills 10 hard-earned lessons from real production incidents. Each one comes with a war story, a solution, and runnable code. Hopefully you won’t have to learn these the hard way.