Blog – Fernando Ruiz on Fernando Ruiz

I Made Claude Opus 4.8 Manage Another AI Agent While I Worked

Sat, 06 Jun 2026 00:00:00 +0000

Have you ever used your best AI model for work that clearly did not deserve your best AI model?

I have. Not because I did not understand model routing. I use cheaper models for cheaper tasks all the time. But when you are deep inside a real codebase, with tests failing, files changing, and context moving fast, it is easy to let your strongest session become the planner, executor, reviewer, secretary, and background worker at once.

AI Pipelines: How I Built Systems That Work While I Sleep

Mon, 11 May 2026 00:00:00 +0000

Most people use AI to generate code, write copy, or fix their lives in a thousand small ways. You feed it something, it spits back something better or more structured. That’s fine. That’s the obvious use case. But one of the highest-value applications I’ve found for AI is building pipelines, specifically with Claude.

Claude is built for this. The model has a strong orientation toward multi-step workflows, tool use, and persistent context. And while there are other capable models out there, including some surprisingly good Chinese models, I’m going to focus on what I’ve actually been experimenting with. The results speak for themselves.

I Built a Medical SaaS With AI. Then I Got Hacked. Here's the Case Study.

Thu, 23 Apr 2026 00:00:00 +0000

The first night I deployed my sister’s medical scheduling system to production, I went to bed feeling like a king. By 9am the next morning, my server’s CPU was pinned at 300%, and someone else was mining cryptocurrency on my rented hardware.

That’s the middle of the story, though. Let me back up.

This is a case study about the SaaS I always wanted to build, the one that finally found me, and everything I broke and learned getting it to work. It’s also the story of a Product Designer who thought he understood software, and discovered the internet is a much stranger, more hostile place than any Figma file ever suggested.

Designing in Words: How AI Turned UX Designers Into Their Own Frontend Engineers

Thu, 09 Apr 2026 00:00:00 +0000

The design review went perfectly. You handed off a Figma file that was pixel-perfect: the right spacing, the right micro-interactions, the hover states, all of it. Three weeks later, the thing that shipped looked like it was built from memory by someone who saw your design once in a dream. Sound familiar?

That story has been playing on loop for the entire history of digital product design. The designer creates. The developer interprets. Something gets lost, always. Sometimes a lot. And the designer files it under “developer error” and moves on to the next project.

Claude Code Skills: The Professional Layer Most Users Ignore

Thu, 19 Mar 2026 00:00:00 +0000

You’re already in Claude Code. You know the basics. You’ve seen what it can do. But every new session starts the same way: you spend the first five minutes re-explaining your context, re-typing the prompts you’ve written a hundred times, and re-establishing the ground rules before any real work gets done.

That friction isn’t a Claude problem. It’s an infrastructure problem. And the fix is a feature most users walk right past: Skills.

Vibe Coding: What AI Won't Tell You Before Building Your First App

Sun, 15 Mar 2026 00:00:00 +0000

There’s a conversation happening thousands of times a day around the world. It goes something like this:

“Hey Claude, I need you to build me a YouTube-like application but without bugs.”

And the [[AI]] responds happily, generates code, and the user thinks they’ve just hired an engineering team for $20 a month. Three weeks later, the application has 47 bugs, nobody knows why login fails on Tuesdays, and the creator can’t change a button color without breaking the payment system.

Spec-Driven Development: The End of Amateur Vibe Coding and the Dawn of Systems Engineering for UX

Tue, 10 Mar 2026 00:00:00 +0000

The concept of [[Vibe Coding]] is appealing. You write in natural language, AI spits out code, and you have a prototype in minutes. It works perfectly for a 100-line script. Try scaling that to a real product, and the system collapses.

I sat down with Ryan Edge to break down exactly how he’s using [[AI]] agents to build complex software. The consensus is clear: relying on chat interfaces to code has a glass ceiling. You lose context, the AI hallucinates, overwrites existing logic, and you end up doing manual work to correct a robot.