João Paulo Cercal

Staff Security Engineer at LastPass

Turning complex, cross-functional challenges into scalable systems, leading with AI-driven workflows and security-by-default engineering.

GPT-6 Astra Is an Operator, Not a Chatbot GPT-6 Astra Is an Operator, Not a Chatbot

GPT-6 Astra Is an Operator, Not a Chatbot

GPT-6 Astra is offered as a model that acts inside existing software. The scores I would read first are the ones that show where it stays inside the task, and where it does not win.

The Cost of the Loop Matters More Than the Score The Cost of the Loop Matters More Than the Score

The Cost of the Loop Matters More Than the Score

Anthropic says Opus 5.5 is at Fable 5.1's level on most work and 40 percent cheaper than Opus 5 at default settings; the useful question is what that does to the cost and the checks of an agent loop.

When AI Decisions Become Software Inputs When AI Decisions Become Software Inputs

When AI Decisions Become Software Inputs

A typed AI judgment can help software route work, provided the application owns the rules, checks uncertainty, and keeps people responsible for consequential decisions.

Working With AI Agents: Stay on the Loop Working With AI Agents: Stay on the Loop

Working With AI Agents: Stay on the Loop

Instead of reviewing every line an AI agent produces, design the environment — specs, tests, checks, and feedback loops — so good outcomes emerge reliably.

Understand the System Before Changing It Understand the System Before Changing It

Understand the System Before Changing It

Good architecture often starts with understanding the system you already have; how requests flow, where dependencies are, and why things ended up the way they are.

Composer clear cache Composer clear cache

Composer clear cache

If you have a problem similar to “End-of-central-directory signature not found.”, you might need to run a composer clear cache command in order to get it working.

Revisiting the layout and the Blog project Revisiting the layout and the Blog project

Revisiting the layout and the Blog project

A project/proof of concept that has been shown good results, it’s about a migration from a PHP website to a static blog, no server costs anymore and web-optimized. Check out a few implementation details.

How to delete all your Git local branches How to delete all your Git local branches

How to delete all your Git local branches

Sometimes after working for a long time, all the remaining local branches are just taking up space. Here's a small snippet to remove all your local branches in one go.

iTerm2 + Zplug = Productivity iTerm2 + Zplug = Productivity

iTerm2 + Zplug = Productivity

After spending a long time of my life using the normal terminal I met a new tool called iTerm2 because a friend of mine a few year ago. And, this week I've discovered the power of zplug. So, let me try to show you how my terminal looks like now.