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Poliatletas · RotinaPet · ViazioSP

Three systems in production, from database to screen.Three systems live, from database to screen.

Three systems in production, written from the database to the screen in Java, Kotlin, and TypeScript.

View selected workDownload backend CVFull-stack CV
Portrait of Caio Vilquer Carvalho
Caio Vilquer Carvalho · São Paulo, BrazilCaio VilquerBackend · Poli-USPJava / Kotlin / TypeScript
Degree
Poli-USP · expected 12/2029
Focus
Backend, from data model to deploy
Stack
Java · Kotlin · TypeScript
Base
São Paulo, Brazil

Three systems in production

Selected work

Poliatletas normalizes results measured in time, distance, and points. RotinaPet filters family and pet before any AI retrieval. Viazio recalculates its ranking when an upstream source fails.

Poliatletas

The athletics management system at Poli-USP

The Poli-USP athletics team uses the system to record meets, results, records, and training, replacing the spreadsheets that went missing every season. More than a hundred people use it, athletes and coaching staff, with an auditable history and public rankings.

Official Poliatletas logo in blue and yellow
NestJS · Fastify · PostgreSQL · Prisma · React · Redis

Key decision

Sports model

Evidence

Public rankings with filters and season comparison

RotinaPet

Shared pet care with an AI and RAG assistant

A whole family cares for the same pet without double-dosing medication or missing a vaccine: every owner sees what was already done, by whom, and when. The AI assistant only ever sees what that family is allowed to see, and it never records anything without a person confirming it.

Official RotinaPet logo in green, black, and yellow
Kotlin · Spring Boot · Angular · PostgreSQL/pgvector · OpenAI

Key decision

Authorization before ranking

Evidence

Household and pet filter applied before hybrid ranking

Viazio

Explainable travel recommendation engine

It picks when and where to travel by weighing holidays, weather, cost, and distance, and shows why each destination landed in that position instead of handing over a single score. When an upstream source goes down, the ranking stays standing and says what was missing.

Horizontal Viazio logo in gold and white on a navy blue grid
Java 21 · Spring Boot · React 19 · PostgreSQL · Resilience4j

Key decision

Decomposable score

Evidence

More than 250 backend tests without network access

Applied research · computer vision

TrackShot CV

Desktop prototype in development

TrackShot uses smartphone video to estimate release speed, angle, and height in shot put without radar or a laboratory.

Open full case study
Two real TrackShot frames with pose tracking over the athlete; the second highlights the implement and its trajectory in yellow

Where I used each technology

Technical profile

Technology and project

Backend
Java, Kotlin, Spring Boot, NestJS, and FastifyViazio, RotinaPet, and Poliatletas
Data and AI
PostgreSQL, pgvector, Prisma, JPA, RAG, and embeddingsRotinaPet, Viazio, and Poliatletas
Frontend
React, Angular, TypeScript, and TanStack QueryAll three selected products
Quality and operations
JUnit, Jest, Vitest, Testcontainers, Docker, and GitHub ActionsDomain, integration, and contract tests

Contact · São Paulo

Get in touch.

I reply to email within one business day. The CVs below carry the full history: the backend one details the projects and the technical decisions, the full-stack one also covers frontend and database work.

São Paulo, SP · Brazil

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