Review-and-retention tool for what you learn on the mats: a 46-node curriculum tree with progressive unlocking, server-graded quizzes, drill logging, streaks and spaced repetition.
Public code. Mostly Java.
28 public repositories on GitHub. The ones below are the projects I keep returning to — APIs for problems I actually care about. Open source, MIT, fork at your peril.
in production · public urls
Running in production.
// Products in the air · source on githubManagement platform for a pilates studio, in daily use: patients, professionals, scheduling and billing. A Spring Boot API behind an Angular admin interface.
Builds your Cartola FC line-up for the round by crossing Brasileirão odds with player metrics: weighted ranking, budget optimisation in cartoletas, formation comparison and a history of past line-ups. Public landing, app behind a login.
🥋FightOssStreak
Review-and-retention tool for jiu-jitsu. Curriculum tree, server-graded quizzes, streaks and spaced repetition.
🏟️cartolaoddsapi
REST API behind Cartola Odds: scores players from odds and form, optimises the line-up against a cartoletas budget and keeps a history of past rounds. JWT-closed.
🧘carlessopilatesapi
REST API for managing patients and professionals of a pilates studio. Domain-driven, fully tested.
🎨carlessopilatesfe
Web interface for pilates studio administration. Patient flows, scheduling, billing.
💻cartolaoddsfe
Angular frontend for Cartola Odds. Prerendered public landing, then the authenticated app: line-up of the round, ranking, favourites and settings.
💰goodfunds
Personal-finance MVP. End-to-end study project — auth, transactions, budgets, monthly close.
⚽goalfather
Elifoot-style football manager. Kotlin backend with a pure domain and a deterministic match engine.
🧩DesignPatterns
Hands-on walkthrough of the GoF design patterns in idiomatic Java. Strategy, observer, builder, decorator.
🔢algoritmos
Algorithm and data-structure practice. Sorts, trees, graph traversals — kept sharp on weekends.
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case study · fightossstreak
Turning what happens on the mats into something you actually retain.
// java 21 · spring-boot 3 · react · docker · 202646curriculum nodes
91quiz questions
9modules, in a tree
~12klines of java + ts
The problem
What you learn on the mats evaporates between sessions. The detail you drilled on Tuesday is gone by Saturday, and there is no structured way to review it — only notes nobody reads twice.
The approach
The curriculum is versioned as data, not code: 46 nodes across 9 modules in JSON, unlocked progressively. Quizzes are graded on the server — the answer never reaches the browser — and each drill feeds a streak and a spaced-repetition schedule. Spring Boot with Flyway and OAuth2, React behind nginx, the whole thing in Docker Compose so dev and production share one topology.
What I learned
The bottleneck was never the code — it was curating content. Writing 91 questions that actually test a concept took longer than the API around them. And a cold-starting backend taught me to build a landing page that renders in full without a single API call.