Paulo Paiva

linkvault is a collaborative link manager that lets you save and organize links, add notes, share public collections, and explore what other users are curating.

Full-stack solution for user management and auth: REST API (Node.js, Express, PostgreSQL, JWT, bcrypt) and React SPA (login, profile, admin user list with pagination and filters). Built as a technical assessment; includes layered backend, unit tests (Jest/Vitest), and documented technical decisions.

LegionIQ helps players analyze data, screenshots and reports to uncover patterns, improve decisions, and refine strategies, all safely and without automation.

Real-time asset price simulator: generates synthetic quotes, aggregates metrics via Kafka, persists to PostgreSQL, and delivers updates via SignalR. Features historical data with date filters, symbols from DB, and live line charts.

Minimal .NET REST API to upload, list, and download images from an S3 bucket, and publish file metadata to AWS SQS for asynchronous processing.

Anonymous community app: browse communities, post, and comment. No sign-up, identity is fingerprint-based.

GraphQL API playground using Hot Chocolate (.NET Minimal API), focused on filtering/sorting and more complex queries over mock JSON data in an interconnected warehouse domain.

A RESTful API built with .NET 9.0 for managing students, teachers, courses, classes, attendance, assignments, and grading with role-based access control.

A complete management system for ABA therapy clinics, including patient and caregiver registration, therapeutic programs, stimuli, protocols, and progress analysis with detailed graphical indicators.

C# Windows print service for kiosk thermal printers. Built to support the Hospital Check-in Kiosk: the React app ran in the browser and could not access USB printers directly, so this service listens on HTTP (port 3000) and receives print jobs from the totem frontend to print receipts, queue tickets, and protocols on thermal printers.

REST API for investment portfolio management with user authentication, wallets, assets, buy/sell transactions, filtering, and portfolio summary calculations.

.NET REST API with CQRS for time-series data, enabling efficient ingestion and querying. Contributed as part of the engineering team that developed this solution for Weatherford International.

An AI-powered clinical assistant designed to help medical professionals generate patient evolution summaries and receive intelligent diagnostic insights, streamlining decision-making, enhancing accuracy, and improving overall efficiency in clinical workflows.

A web platform developed to help medical professionals manage their full schedules and handle appointment and service requests efficiently, improving daily operations and optimizing hospital workflows.

This browser extension helps you review and unfollow multiple people you follow on LinkedIn directly from the "Following" page, without leaving the page or using a separate popup list.

An intuitive self-service kiosk system for hospitals that streamlines patient check-ins, appointment scheduling, and navigation within hospital facilities.

A modern and secure web platform built for allowing patients to manage personal information, medical history, invoices, and appointments, enhancing patient autonomy and streamlining administrative workflows.

A lightweight macOS menu bar application that displays the current USD to BRL exchange rate in real time with automatic updates every 60 seconds.

An anonymous posting application where anyone can share anything – texts, drawings, or a combination of both, with dark mode support and no authentication required.