Prompt Caching: Why Long Repeated Prompts Don't Cost So Much

Posted on Mon 09 November 2026 in Beginner Guide • Tagged with GenAI, LLM, prompt-caching, cost, performance, API, production

The Problem With Long System Prompts

If you've built anything with an LLM API, you've probably added a system prompt. At first it's a sentence or two. Then you add instructions. Then examples. Then context about your product. Before long, your system prompt is a few hundred lines and every …


Continue reading

Async vs Sync in FastAPI — When It Actually Matters

Posted on Tue 29 September 2026 in Tutorial • Tagged with FastAPI, Python, async, performance, beginner

Why This Confuses Beginners

One of the first things that trips people up in FastAPI is seeing both def and async def used for routes, sometimes in the same codebase, and not knowing which one to use or why it matters. Some tutorials use async def everywhere out of habit …


Continue reading