Paulo Junqueira | Full Stack Developer
Full stack developer (C#/.NET, React and Node.js) and Agronomy student. I build software that reaches the field, from the farmer's WhatsApp to the sensor in the soil.
Projects
Projects I designed and built, mostly for agriculture. Where there is a link, you can try it or read the code.
Gleba (2026)
I built it out of my own field visits: a notepad for notes, a calculator without the right formula, photos scattered in the gallery and, most of the time, no signal. Gleba (the word for a plot of land) solves that on the phone: 50+ agronomic calculators with step-by-step math, a visit journal with photos, audio, video, weather and location, and PDF or Word reports. It works fully offline and syncs when the connection comes back. I built the Flutter app, the Node.js API with Azure and Auth0, and the Next.js page for shared reports.
Flutter, Node.js, Express, Prisma, Azure, Auth0, Next.js
https://www.linkedin.com/posts/paulocesarjunqueira_agtech-agronomia-tecnologianocampo-activity-7483233955245289473-lzvx
Zé Agro (2025)
AI assistant on WhatsApp that answers farmers' questions about crops, pests, livestock, field calculations and weather, even from a photo of the crop. Built from scratch: Node.js back end with GPT-4o and MongoDB, weather and plant-identification API integrations, and the landing page.
Node.js, WhatsApp API, GPT-4o, MongoDB, Express, Clima API, PlaNet API
https://www.zeagro.online https://wa.me/551731982446 https://www.linkedin.com/posts/paulocesarjunqueira_agrotech-inteligenciaartificial-nodejs-activity-7376375598111293440-X5B2
O Jogo do Agrônomo (2026)
A pixel-art side-scrolling runner about a newly graduated agronomist's first day on the job: jump, slide, dodge the hazards of the field and deliver the report at the farmhouse before the 80 mm rainstorm. The humor comes from real agronomist and farmer mishaps, and good practice is what wins: prescriptions, PPE and the right spraying window. It has a prologue with recorded voice-over synced to the character's mouth, six fields and a choice between a male or female agronomist. Built with Phaser 4, TypeScript and Vite; it runs in the browser, installable and offline (PWA), and as an Android app with Capacitor. The playable chapter ends at the farmhouse; the rest of the season is the next step.
Phaser 4, TypeScript, Vite, PWA, Capacitor 8
https://agronomo.paulojunqueira.com/
Consulta CAR (2026)
Looking up a rural property in CAR (Brazil's Rural Environmental Registry) meant downloading the SICAR shapefile and importing it into QGIS by hand. I built a Python (FastAPI) API that imports the official data and returns the property with its polygon from the CAR code, plus a QGIS plugin that queries the API and draws the result on the map, colored by status.
Python, FastAPI, SQLite, PyQGIS, QGIS Plugin
https://www.linkedin.com/posts/paulocesarjunqueira_agtech-geoprocessamento-qgis-activity-7492942945814466560-5v7y
Pluviômetro Digital (2026)
Android app to log rainfall in the field, 100% offline: calendar, dashboard with drought alerts and year-over-year comparison, PDF reports and data backup. It came from the routine at the farm, where rainfall was jotted down loosely and the history got lost. Built with Flutter and SQLite; the APK is on GitHub.
Flutter, Dart, SQLite, PDF
https://github.com/opaulojunqueira/pluviometro_app https://www.linkedin.com/posts/paulocesarjunqueira_agtech-agronomia-agricultura-activity-7432503574405865472-GLyH
Buffer Rápido + Área (2026)
QGIS plugin that creates a layer buffer and instantly calculates its area in m² and hectares. Fewer clicks for a task that comes up all the time in GIS work. Open source, in Python/PyQGIS.
Python, QGIS Plugin, PyQGIS, Geoprocessing
https://github.com/opaulojunqueira/quick_buffer_area
Zé Agro Web (2025)
The web version of Zé Agro: farmers draw their fields on a map and see the size in hectares, follow the weather and chat with the assistant. React and TypeScript front end, with sign-in through WhatsApp.
React, TypeScript, Tailwind CSS, Vite, Shadcn/UI, API REST, WeatherAPI
https://web.zeagro.online/
Agro4U (2023)
My undergraduate thesis at FATEC Jales, backed by an undergraduate research scholarship: a system that triggers irrigation on its own based on soil moisture, using Arduino and sensors. It became a paper published in the Centro Paula Souza institutional repository.
Arduino, IoT, Sensores, C++, Web Dashboard
https://github.com/Agro4U https://ric.cps.sp.gov.br/handle/123456789/16631
Fitlyx (2026)
A social network for people who train: post workouts, log achievements and follow others. Personal project in React, TypeScript and Node.js, with Google sign-in.
React, TypeScript, Node.js, Google API
https://fitlyx.vercel.app/
About
I graduated in Internet Systems from FATEC Jales. At Loop Sistemas I work with C# and .NET: .NET MAUI apps, ASP.NET APIs and SQL Server databases.
I started with web and mobile development (Node.js, React, Flutter) and, since 2022, I've been shipping my own projects. Before coding professionally, I was an apprentice at an agribusiness.
I come from a family of farmers and always liked being around, helping with whatever was needed. That is where Agronomy came from: I wanted to understand the routine of the people who will use what I write. Outside work and college, I enjoy horseback riding and being close to nature.
Contact
contato@paulojunqueira.com