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Full-stack engineer

Rolando Medina Rosner

For the past three years I've worked on the software Paraguay's public hospitals use every day. I mostly handle the backend and deployment, but I also led the rewrite of the frontend to React and built an offline version for the hospitals where the connection drops for days at a time.

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Asunción, Paraguay · open to relocation

Mostly backend, but I do the whole stack.

I'm on a three-person team that builds the hospital information system clinical staff use every day across Paraguay's public hospitals. I own the inpatient clinical modules, and I'm usually the one the team comes to for the backend, deployment, and the harder frontend work.

The part I actually enjoy is the plumbing: taking a legacy module nobody could maintain and rebuilding it as a clean TypeScript app with a proper API, or keeping a hospital running through days with no connection. Lately it's meant getting a self-hosted model to answer questions about the database without ever being able to change the data.

Outside work I self-host almost everything I build: my own servers, CI, and tunnels. That's where most of my infrastructure and deployment habits come from.

Experience

Mar 2024 — present

Asunción, Paraguay

Software Engineer

Taiwan ICDF — National Hospital Information System

One of three engineers on the system. I handle most of the frontend, the backend internals, and deployment, and I led both the move off the legacy code to React and the switch to containerized deploys with CI/CD.

  • Own inpatient clinical modules end-to-end — physician orders, diagnoses, nursing workflows, pharmacy and medication requests, and medical-history PDF export — used daily by clinical staff nationwide.
  • Rebuilt the largest legacy module from unmaintainable JSP and jQuery into structured TypeScript, and restructured its Struts backend into a DAO/DTO JSON API; replaced webpack with rsbuild, cutting build times by ~60%.
  • Chose React over Lit for the rewrite (Lit couldn't meet SSR requirements), built the entire project setup, and shipped the three most complex modules to production.
  • Building an offline-first PWA so rural hospitals keep operating through multi-day connectivity loss — service-worker background sync, an IndexedDB outbox, and version-tagged DTOs that migrate stale client data on reconnect.
  • Replaced script-based WAR deployments with a two-image Docker Compose setup; prototyped a k3s cluster with Helm and evaluated OpenYurt for edge-deployed hospital servers.
  • Self-hosted a language model (vLLM, quantized Gemma) and built the schema, retrieval, and prompt layer for natural-language-to-SQL queries over the clinical database.
  • TypeScript
  • React
  • Next.js
  • Java / Struts
  • PostgreSQL
  • Docker
  • k3s
  • PWA
  • Self-hosted LLM

Aug 2023 — Feb 2024

Asunción, Paraguay

DevOps Engineer Jr.

ROSHKA S.A.

Started as a frontend developer intern on a banking web app and was hired full-time into an engineering role at the internship's conclusion.

  • Built Jenkins CI/CD pipelines using Git Flow and GitHub Flow, containerized services with Docker, and integrated SonarQube quality gates.
  • Contributed React frontend work to a banking web application as an intern; hired into a full-time engineering role at its conclusion.
  • Jenkins
  • Docker
  • SonarQube
  • React
  • Git Flow

Selected work

Two production systems I built and run, a research project, and a game you can play in the page.

dyr-ai.rad710.com/login
Text-to-SQL RAG

Featured

Text-to-SQL RAG

LiveCode

Ask a question in plain language and get the answer from the database, without writing any SQL yourself.

It works out which tables matter, writes a SELECT, runs it, and shows the result as a table or chart. Nothing it generates can touch the data: every query is checked first and rejected if it isn't read-only. The whole thing runs on my own hardware, with no external API calls.

Sign in with [email protected]/DemoPass123

  • FastAPI
  • Python
  • React 19
  • Tailwind v4
  • ChromaDB
  • sqlglot
  • Ollama / vLLM
  • PostgreSQL
  • MySQL
  • Docker
dyr.rad710.com
D y R Transportes

Featured

D y R Transportes

LiveCode

The tool a grain-transport company uses to track its trips, cargo, and driver pay.

It records every trip, works out what each driver is owed, and produces the reports the national transport regulator asks for. I built all of it: the React frontend, the Flask and MySQL API, and the self-hosted pipeline that deploys it.

Sign in with [email protected]/DemoPass123

  • React 19
  • TypeScript
  • Vite
  • Material UI
  • Flask
  • SQLAlchemy 2.0
  • MySQL
  • Docker
  • Jenkins

Sentiment Analysis on Financial News

My final-year thesis: comparing NLP models (finBERT, pyABSA) at reading the tone of financial news, then checking it against how the stock actually moved. The department flagged it as one of the standout projects of the 2023 class.

  • PyTorch
  • finBERT
  • pyABSA
  • pandas
  • scikit-learn

Featured

Theme Park

Run itCode

A rollercoaster on a spline track, a water simulation and hand-written GLSL shaders — my computer-graphics final project, now running in the browser.

Written in C++ with OpenGL, FLTK and OpenAL for Windows. I compiled it to WebAssembly without rewriting the renderer: the browser has no fixed-function OpenGL, so the port supplies its own immediate-mode pipeline, matrix stacks, lighting and picking, plus stand-ins for FLTK, GLU/GLUT, OpenCV and ALUT. It runs slower in the browser than the native build.

  • C++
  • OpenGL
  • GLSL
  • WebAssembly
  • Emscripten
  • FLTK
  • OpenAL
The Fallen Kingdom

A C++ text adventure compiled to WebAssembly. About 330 KB, downloaded only when you press play.

The Fallen Kingdom

Code

A text adventure I wrote in C++ in 2021, compiled to WebAssembly. Play it above.

21 rooms, 24 enemies, and a lamp that runs out. Same game logic as the Windows build.

  • C++17
  • WebAssembly
  • Emscripten

Skills

The tools I work with most, by area.

Languages

  • TypeScript
  • Python
  • Java
  • SQL
  • C / C++

Frontend

  • React
  • Next.js
  • PWA & service workers
  • IndexedDB
  • Tailwind CSS
  • Material UI
  • shadcn/ui

Backend

  • Java (Struts, Spring Boot)
  • Python (Flask, FastAPI)
  • REST API design
  • SQLAlchemy
  • MySQL
  • PostgreSQL

Infrastructure

  • Docker
  • Kubernetes (k3s)
  • Terraform
  • Proxmox
  • Jenkins
  • GitLab CI
  • Linux

AI / Data

  • RAG
  • Self-hosted LLMs (vLLM)
  • ChromaDB
  • PyTorch
  • scikit-learn
  • pandas

Languages

  • Spanish

    Native

  • English

    TOEFL iBT 6/6 · CEFR C2

  • German

    B1

  • Mandarin

    Elementary

Let's talk

Open to full-stack and backend roles, remote or relocation. The fastest way to reach me is email.

[email protected]
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