danielnvcd:~

about profile

About me

Developer focused on backend, automation and the integration between hardware and software.

I'm a developer focused on backend, automation and the integration between hardware and software. I specialize in building systems, APIs and web platforms for access control and solutions connected to physical devices.

My main stack is Spring Boot and FastAPI on the server, React in the browser and PostgreSQL or MySQL for data. I pick based on the problem: not everything needs the same language or the same architecture.

Hardware and architecture

Beyond the code, I get hands-on with the hardware and the architecture. I have experience building secure admin panels and working with:

  • NFC/RFID technology integration and serial communication
  • IoT systems and connection with physical devices
  • Integration with biometrics and security APIs (Hikvision and ZKTeco)
  • Backend architecture, security and authentication

Infrastructure

I also manage the operational infrastructure. I build, configure and administer Linux servers, from self-hosted machines to dedicated servers and enterprise VPS. Here I handle the full cycle:

  • VPS and dedicated server management
  • Installation of HPE and Lenovo physical servers
  • Dockerizing and deploying APIs and web applications
  • Networks with Ubiquiti gear, Nginx as reverse proxy, domains, SSL and Cloudflare
  • Hardening, security and administration of Linux services
  • Infrastructure automation and monitoring

matrix
  • API Backend and APIs REST services in Spring Boot and FastAPI, with Socket.IO when real time is needed, and stable contracts between systems.
  • SEC Security and authentication JWT with rotating refresh, TOTP 2FA, role-based permissions, rate limiting and validation of uploaded files.
  • SQL Databases Relational modelling in PostgreSQL, MySQL and SQLite, Flyway migrations, indexes and query optimization.
  • IOT Hardware and IoT NFC/RFID, serial communication, Arduino/ESP32, custom PCB and ESC/POS thermal printers.
  • BIO Biometrics and access control Integration with Hikvision (ISAPI) and ZKTeco: face recognition, fingerprint and MIFARE cards.
  • NIX Linux servers Administration of VPS and dedicated servers, systemd, cron, logs and service hardening.
  • DKR Docker and deployment Dockerizing APIs and web applications, Docker Compose, non-root users and repeatable deployments.
  • NET Networking and domains Nginx as reverse proxy, TLS, DNS, Cloudflare and tunnels to expose services without opening ports.
  • HW Physical servers and networks Installation of HPE and Lenovo servers, and networks with Ubiquiti gear: switches, access points, VLANs and monitoring.
  • FRT Frontend React SPAs with Vite and TailwindCSS, plus desktop interfaces with PySide6 (Qt 6).
  • AUT Automation and monitoring Scheduled tasks, validated bulk imports, Prometheus metrics and infrastructure alerts.