Full-Stack Developer

Hi, I'm William.

I'm a full-stack developer at Italy's largest software house, working on the e-invoicing and tax-compliance infrastructure that Italy's tax authority and EU businesses rely on. In my spare time, I design and maintain self-hosted projects of my own, from the backend to the systems that run them.

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Photo of William Solari

William Solari

Full-Stack Developer

Languages

IT Italian Native
EN English C1
ES Spanish B1
DE German A2

About

Intern to product owner in under a year

At Zucchetti I'm the sole lead developer of corrispettivi telematici, a software for transmitting daily point-of-sale receipt data to Italy's tax authority, built to its official technical specification. I also contribute to Peppol-network integrations on Zucchetti's accredited Peppol Access Point. Separately, I work on digital signatures, including FEA, FES, and FEQ.

I studied Electronic & Computer Engineering at the University of Pavia before trading the last few exams for a full-time seat at Zucchetti.

Languages & Frameworks

Java Spring Boot JavaFX JavaScript HTML CSS Node.js

Data & Infrastructure

SQL PostgreSQL MySQL SQL Server MariaDB H2 SQLite Docker Git

Integration & Domain

Peppol (SMP/SML) REST SOAP WebSocket MQTT Schema validation Digital signatures

Experience

Where I've worked

  1. Full-Stack Developer

    Zucchetti - Apr 2025 - Present

    • Lead developer of "corrispettivi telematici", a software for transmitting daily point-of-sale receipt data to Italy's tax authority.
    • Built Peppol-network integration features for Digital Hub, handling schema validation and message routing for cross-border invoices between Italian and EU businesses.
    • Built REST/SOAP integrations connecting invoicing and signature services to SdI and NSO, and developed qualified e-signature support (FEA/FES/FEQ, PAdES/CAdES/XAdES).

  2. Java Developer - Internship

    Zucchetti - Oct 2024 - Mar 2025

    • Moved key scheduled jobs from single-threaded to multi-threaded execution, cutting processing bottlenecks and lock contention.
    • Built a JavaFX desktop application to monitor and manage Tomcat deployments across multiple servers.
    • Helped drive adoption of pure-Java tooling for internal Digital Hub utilities.

Selected projects

Independently maintained, end to end

Komm

Self-hosted voice, video & text chat

JavaJavaFXSpring BootWebRTCmTLSWindowsLinux
Flip for details

Komm

Self-hosted voice, video & text chat

A self-hosted voice, video, and text chat platform built end-to-end across five repositories. Engineered the WebRTC audio pipeline using AEC3 echo cancellation, RNNoise noise suppression, and Silero VAD for voice activity detection. Designed an mTLS trust model securing communication across every service.

kommvoice.com komm (client) komm-server komm-server-launcher komm-hub komm-launcher

QueryExe

Cross-platform SQL client

JavaJavaFXMySQLMariaDBPostgreSQLSQL ServerH2SQLite
Flip for details

QueryExe

Cross-platform SQL client

A free, cross-platform desktop client for relational databases (MySQL, MariaDB, PostgreSQL, SQL Server, H2, and SQLite). Multi-connection SQL editor with autocomplete, concurrent query execution, and direct result-grid editing, distributed through a self-updating launcher for Windows and Linux, built and released via GitHub Actions.

query-exe query-exe query-exe-launcher

Smart Home

Zigbee smart home, sensor-fused

JavaSpring BootZigbeeMQTTWebSocketCapacitorJs
Flip for details

Smart Home

Zigbee smart home, sensor-fused

An Android app for real-time monitoring and control of a Zigbee-based smart home, integrating multiple sensors over MQTT and WebSocket. The Spring Boot backend fuses power-consumption, tilt, and vibration readings to detect door state and flag stuck conditions automatically, with role-based admin access and activity logging.

smart-home-mobile smart-home-mobile smart-home-server

Marina Labs

Singapore Peppol / InvoiceNow validator

JavaSpring BootPeppolDocker
Flip for details

Marina Labs

Singapore Peppol / InvoiceNow validator

A Singapore Peppol/InvoiceNow document validation platform featuring a two-stage XSD and Schematron pipeline that validates UBL e-invoices against official Singapore Peppol specifications and generates PDFs through the official XSLT stylesheets, packaged as a Java/Spring Boot + Node.js full-stack app with one-command Docker Compose deployment.

GitHub marina-labs

EmojiFX

JavaFX emoji rendering library

JavaJavaFXMaven Central
Flip for details

EmojiFX

JavaFX emoji rendering library

A JavaFX library that brings proper emoji rendering to desktop apps, with support for multiple emoji styles. Published on Maven Central for any JavaFX project to pull in directly.

Maven Central emoji-fx

Contact

Let's talk

Whether it's a question about one of the projects above or something new entirely, my inbox is open.

contact@williamsolari.com linkedin.com/in/william-solari github.com/B077AS