Henrique KasprzakI build systems that read the physical world and keep the data honest.
Full-stack developer in Curitiba, Brazil — Go on the backend, React on the front. At Metropolys I write the services behind a smart-city platform: plate and face recognition, camera control, telemetry from sensors across a city, and the screens operators watch it all from. Off the clock I build complete systems on my own, end to end.
Open to backend and full-stack roles, remote or in Curitiba.
- Now
- Developer at Metropolys
- Focus
- Go services, real-time data
- Based in
- Curitiba, Brazil
- Degree
- Computer Engineering, 2026
One plate, end to end
The path a single detection takes through the recognition service I wrote at Metropolys. Each stage adds what it knows.
Event payload — Stage 6/6
{
"plate": "RJK4C19",
"alert": {
"reason": "stolen_vehicles",
"priority": 1,
"channel": "operations_dashboard",
"dispatched_at": "2026-09-17T13:42:09Z"
}
}Selected work
Five systems, written up the way I'd explain them to another engineer: what the problem actually was, what I chose, and what it cost.
2024 — present
Xanadu Fleet
Inspections that survive with no signal
A fleet inspection, fueling and maintenance system for a transport company: versioned checklists filled in on the roadside with no connectivity, records that are superseded rather than edited, and a signed evidence chain anchored to write-once storage.
Built with: Go, PostgreSQL, htmx, PWA, S3 Object Lock (WORM), Ed25519, Goose, GitHub Actions, MagaLU Cloud
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2024 — present
Smart-city platform
A city's cameras and sensors, in one place, in real time
My day job at Metropolys. Go services that ingest plate reads, face matches, transit feeds, traffic and weather telemetry, and the parts of the web product where operators search a plate, follow a vehicle across the city and receive watchlist alerts.
Built with: Go, TypeScript, React 19, PostgreSQL / PostGIS, Redis, MQTT, WebSocket, Kubernetes, Prometheus
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2026 — present
Manutenção Lavoura
A maintenance logbook that fits in one binary
Farm-equipment maintenance for two people — an agronomist and a farm manager — recorded on a phone in the field, often without signal. One Go binary and one SQLite file on a small server, with an offline outbox and a photo queue that never hold a record back.
Built with: Go, SQLite, htmx, PWA, Caddy, systemd, GitHub Actions
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2025
Mini Estufa
A greenhouse that reports on itself, from ADC pin to browser
My capstone project. I soldered the sensors, calibrated the readings, wrote the Go API that broadcasts them over WebSocket, and built the React dashboard that draws them — the full path from a voltage to a chart.
Built with: Go, gorilla/websocket, React 19, Vite, Tailwind, Recharts, Supabase, MQTT, ESP32
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2025 — 2026
Xanadu Transportes
A haulage company's first website
A transport company whose customers found it by phone number alone. A single prerendered page that loads fast on a truck-stop connection, puts a WhatsApp conversation one tap away, and only loads analytics after the visitor consents.
Built with: Next.js 15, React 19, Framer Motion, Cloudinary, Google Analytics 4, Vercel
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