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Substack

Lab

Experiments and tools I’ve built.

Tools, games, and experiments I’ve built over time. What I made, why I made it, and what I learned.

Guia Brain previewGuia Brain
01Personal intelligence system

Working system

Guia Brain

A local-first AI memory system that keeps context, decisions, and knowledge available to the models you already use.

Open
Behind the build

Guia Brain

A local-first AI memory system that keeps context, decisions, and knowledge available to the models you already use.

Why I built it

I switched models and realized that months of context were stuck in the previous service. I started Guia Brain to solve that problem.

What I learned

You will switch models many times and your memory needs to remain yours.

Findli previewFindli game scene
02Playable AI product

Playable game · beta

Findli

A hidden-character game built around richly detailed scenes. Play weekly challenges, compete, or turn a photo into the character your friends have to find.

Open
Behind the build

Findli

A hidden-character game built around richly detailed scenes. Play weekly challenges, compete, or turn a photo into the character your friends have to find.

Why I built it

I wanted to test personalization as part of the fun. Instead of only configuring a game, the person becomes part of the scene.

What I learned

Personalization creates the surprise; recurring challenges, fair difficulty, and competition keep the experience alive.

WataRank previewWataRank cards
03Trading-card ranking game

Interactive edition · 2026

WataRank

A social ranking turned into a card game: compare attributes, open the original leaderboard, and cast your own take.

Open
Behind the build

WataRank

A social ranking turned into a card game: compare attributes, open the original leaderboard, and cast your own take.

Why I built it

I wanted to turn abstract rankings into something visual, comparable, and playful — a card you understand at a glance and want to debate.

What I learned

The card works as a product unit: it compresses data, identity, and opinion into an interface that is easy to explore and share.

World Cup 2026 Simulator previewWorld Cup 2026 simulator
04Sports scenario game

Live simulator · 2026

World Cup 2026 Simulator

A complete 48-team World Cup simulator: enter scores, follow qualification, and play every scenario through the final.

Open
Behind the build

World Cup 2026 Simulator

A complete 48-team World Cup simulator: enter scores, follow qualification, and play every scenario through the final.

Why I built it

The new World Cup format made the bracket hard to picture. I wanted to turn it into a game that recalculates the tournament as you choose each result.

What I learned

Official data, qualification rules, and personal simulations need to coexist without becoming confused. Separating those layers made the product both trustworthy and fun.

JOBareo previewJOBareo experience
05Career product

Live product · early stage

JOBareo

AI interview preparation based on the company and the role.

Open
Behind the build

JOBareo

AI interview preparation based on the company and the role.

Why I built it

Preparing for an interview without the role and company context only helps so much. That context changes which questions actually matter.

What I learned

Interview preparation becomes more useful when it uses the real role context and happens close to the interview itself.

Rio Crime Map previewRio Crime Map
06Public data · open source

Public tool · 2026

Rio Crime Map

A map for exploring Rio’s police records by area, comparing time periods, and understanding the numbers in context.

Open
Behind the build

Rio Crime Map

A map for exploring Rio’s police records by area, comparing time periods, and understanding the numbers in context.

Why I built it

The data was public, but understanding each area meant working through spreadsheets and administrative boundaries. I wanted to make that information easier to explore.

What I learned

Numbers need context: time periods, population, and boundaries change the interpretation. Explaining the limits of the data is part of the product.

Read the full story
demonstration data
07Local-first product

Built and operated

Job Application Agent

A dashboard, local API, and automation queue for researching, evaluating, executing, and tracking job applications.

Open
Behind the build

Job Application Agent

A dashboard, local API, and automation queue for researching, evaluating, executing, and tracking job applications.

Why I built it

The operation was spread across sources, documents, ATS products, and manual records, with no single state for decisions and tracking.

What I learned

Separating product code from private data, modeling the queue, and requiring external confirmation made the automation usable day to day.

Read the full story
Inteligência à Brasileira previewSubstack publication
08AI publication for Brazil

Active publication · in Portuguese

Inteligência à Brasileira

A Portuguese-language publication that helps Brazilians understand artificial intelligence without the jargon — direct, accessible, and grounded in our context.

Open
Behind the build

Inteligência à Brasileira

A Portuguese-language publication that helps Brazilians understand artificial intelligence without the jargon — direct, accessible, and grounded in our context.

Why I built it

Much of the AI conversation reaches Brazil translated or stripped of local context. I created a place to explain what matters in a practical, Brazilian voice.

What I learned

Accessibility is not about oversimplifying. It is about using examples, language, and questions that connect technology to real life.