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News, guides, and updates from Curtis Foster.

Hero image for blog post: Prompt engineering is table stakes. System-prompt engineering is the real skill

Prompt engineering is table stakes. System-prompt engineering is the real skill

Prompt engineering can make a demo work. System-prompt engineering makes an LLM product behave reliably when users, tools, and edge cases arrive.

December 21, 2025· 12 min read
Hero image for blog post: A founder’s guide to avoiding AI vendor lock-in without slowing down

A founder’s guide to avoiding AI vendor lock-in without slowing down

You do not need to build every AI component yourself. You need a small model abstraction, clean boundaries, and a plan for switching before switching becomes urgent.

December 12, 2025· 12 min read
Hero image for blog post: How I ship a new AI product in a weekend and the three things I refuse to skip

How I ship a new AI product in a weekend and the three things I refuse to skip

A practical weekend process for building an AI MVP without confusing speed with recklessness. Ship fast, learn in public, and keep the safeguards that protect users.

December 3, 2025· 13 min read
Hero image for blog post: AI guardrails aren't a filter. They're an architecture

AI guardrails aren't a filter. They're an architecture

A production AI product needs controls around data, tools, models, users, and recovery paths. One moderation filter cannot carry that load.

November 25, 2025· 14 min read
Hero image for blog post: Multi-model orchestration: why I stopped betting a whole product on one model

Multi-model orchestration: why I stopped betting a whole product on one model

A production AI product should not depend on one model's price, latency, or behavior. Here is how I use routing, fallbacks, and evaluation to spread that risk.

November 16, 2025· 15 min read
Hero image for blog post: The real cost of an AI feature: instrument AI cost before it surprises you

The real cost of an AI feature: instrument AI cost before it surprises you

An AI feature costs more than its model call. Learn how to measure retries, tokens, latency, storage, and AI unit economics before your bill gets ahead of you.

November 7, 2025· 12 min read
Hero image for blog post: What long-term memory actually takes in a production LLM application

What long-term memory actually takes in a production LLM application

LLM memory is not a bigger context window. It is a data system with rules for capture, retrieval, correction, privacy, and cost.

October 29, 2025· 16 min read
Hero image for blog post: RAG is a data-quality problem, not a search problem

RAG is a data-quality problem, not a search problem

Most RAG failures begin before vector search runs. Fix the source data, ownership, and update process, and retrieval becomes far easier to trust.

October 21, 2025· 15 min read
Hero image for blog post: The eval loop is the product: why I build evaluations before features in any AI app

The eval loop is the product: why I build evaluations before features in any AI app

AI evals are not a final QA step. They are how you decide what to build, what to fix, and whether an AI product deserves user trust.

October 12, 2025· 12 min read
Hero image for blog post: Why your AI demo works and your AI product does not

Why your AI demo works and your AI product does not

The last 20% of an AI product is where reliability, evaluation, cost, and user trust get decided. Here is how to close the gap.

October 3, 2025· 14 min read

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