In 2023, the trick was knowing how to word a prompt. In 2026, every serious AI model follows instructions well enough that phrasing stopped being the bottleneck. The bottleneck is now what information the model has when it answers. That is context engineering, the discipline of designing everything the model sees, not just what you say to it. This is the complete guide.

The Moment I Stopped Thinking About Prompts

I had spent three days rewriting a prompt.

The system was a customer support agent. It was giving inconsistent answers, sometimes accurate, sometimes confidently wrong. I tweaked the wording. I restructured the instructions. I added examples. I tried different models. I moved sentences around. I experimented with different formatting.

Nothing worked reliably.

Then a colleague asked a question that changed everything:

"What information does the model actually have when it answers?"

Not "what are you telling it to do", that was the prompt, and I had optimised it to death.…