Full Stack Developer · React / Node.js

Online ordering system for a local pizzeria. Configurable catalog with option groups, prices always quoted on the backend, anonymous checkout with price snapshots and an admin panel.

• Price is never computed on the client. POST /api/orders/quote validates product, options and ownership on the backend and recalculates everything before creating the order.
• Each order line stores a snapshot of product_name, unit_price and options as JSONB: if the price changes tomorrow, past orders do not. The insert of orders + order_items runs inside a transaction.
• 8 test suites with Vitest + Supertest. app.ts is split from index.ts so the API can be tested without binding a port. Raw SQL with node-pg-migrate and a repositories/ layer instead of an ORM.

After inactivity, the first load may take ~20–30s (Render Free).

Deployed job-market intelligence: collects technical listings with Playwright, normalizes them in PostgreSQL and surfaces them in a dashboard with stats by source, seniority, contract type and salary.

• FastAPI with a repository pattern: SQL is encapsulated outside the routes, so the API can be tested end to end without touching the real database.
• Backend covered by 6 test files and frontend by 10 suites over stats, filters, detail and pagination. The scraper runs in loop mode and filters by country; FastAPI serves the SPA itself.
• Alembic migrations and GitHub Actions CI with separate workflows for backend, frontend, scraper, scheduled scrape, backup and health check.

After inactivity, the first load may take ~40s (Render Free).

Full e-commerce platform built around a clear buying experience: manageable catalog, persistent cart and multi-step checkout with confirmation.

• Transactional checkout in PostgreSQL: the order and the inventory update are written in the same transaction, so stock never desyncs if something fails.
• Public catalog without login, with search, categories, tags and price range. Sign-in is only required to buy, view history and administer.
• Backend hardening: Helmet, rate limiting, input validation and JWT with bcrypt. Admin panel for products, users and orders.

The page opens quickly; the catalog may take ~20–30s if the API was idle (Render Free).

Real-time environmental monitoring with ESP32 sensors. From sensor to dashboard: API-key ingestion, cloud Postgres and historical charts.

• The full data path: the ESP32 + SHT3X firmware does POST /api/ingest with an API key into Neon, and Next.js reads it to render the dashboard. Firmware lives in firmware/esp32-sht3x, inside the same repo.
• The device samples every 5 min but uploads in batches every 30: Neon suspends compute after ~5 min idle, so writing every 5 min burned the 100 free CU-hours in ~16 days. Batching brings it down to ~33 CU-h/month.
• Raw data kept for 30 days with older history served from hourly aggregates. Charts with threshold lines, today-vs-yesterday comparison and weather / air-quality widgets via Open-Meteo.