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Federico Calò — Backend Developer & ML Engineer

Federico Calo

Ingegnere Full-Stack di Intelligenza Artificiale

Bari, Puglia, Italy

702Articles IT
1.404Multilingual
512Development Tools
18Languages

Who am I

Backend & ML Engineering

Full-stack engineer with a focus on distributed architectures, Clean Architecture, and ML engineering. I design and implement scalable systems using Angular 21 SSR, Spring Boot 3.4 Clean Architecture, FastAPI with RAG, and Python 3.12. I write code with zero compromises on quality, testability, and maintainability.

Technical writing

I publish ~50 technical articles per year: deep-dive on algorithms, software patterns, system design, database optimization, event-driven microservices. 618 articles in Italian, 1,236 in 18 languages. I don't write to make numbers — I write for developers looking for rigorous content, not hype.

Dev-tools open source

Development of open-source dev-tools with a technical focus: IBAN generators (MOD-97 ISO 13616), fiscal validators (50+ countries), network tools (DNS, SSL, WHOIS). Each tool is implemented with correct algorithms, 80%+ test suites, API documentation. Practice makes the best teacher.

Stacks & Architectures

Frontend

  • Angular 21 SSR
  • TypeScript 5.9 strict mode
  • Signals + OnPush
  • Web performance (LCP < 2.5s)
  • Accessibility WCAG 2.1 AA

Backend & Architecture

  • Spring Boot 3.4 + Java 21
  • Clean Architecture 4-layer
  • Microservizi event-driven
  • PostgreSQL 16 + optimization
  • Redis Stack + caching

ML & DevOps

  • FastAPI + async Python
  • RAG + RediSearch HNSW
  • sentence-transformers + embeddings
  • Ollama on-prem (llama3.1:8b)
  • Claude Code · GitHub Copilot

Quality & Testing

  • TDD + 80%+ coverage
  • JUnit 5 + Testcontainers
  • pytest + fixtures
  • E2E (Playwright)
  • Observability (Prometheus, Grafana, Loki)

Education & Skills

My academic path and the technologies I master

Professional Certifications

8 certifications earned

New
Reinvention With Agentic AI Learning Program
Display

Reinvention With Agentic AI Learning Program

Anthropic

December 2024
New
Agentic AI Fluency
Display

Agentic AI Fluency

Anthropic

December 2024
New
AI Fluency for Students
Display

AI Fluency for Students

Anthropic

December 2024
New
AI Fluency: Framework and Foundations
Display

AI Fluency: Framework and Foundations

Anthropic

December 2024
New
Claude with the Anthropic API
Display

Claude with the Anthropic API

Anthropic

December 2024
Master SQL
Display

Master SQL

RoadMap.sh

November 2024
Oracle Certified Foundations Associate
Display

Oracle Certified Foundations Associate

Oracle

October 2024
People Leadership Credential
Display

People Leadership Credential

Connect

September 2024

Linguaggi & Tecnologie

Java
Python
JavaScript
Angular
React
TypeScript
SQL
PHP
CSS/SCSS
Node.js
Docker
Git
💼
12/2024 - Present

Custom Software Engineer Analyst

Accenture

Bari, Puglia, Italy · Hybrid Analysis and development of IT systems using Java and Quarkus in the Health and Public Sector. Continuous training on modern technologies for creating customized and efficient software solutions and agents.

💼
06/2022 - 12/2024

Software Analyst and Back End Developer Associate Consultant

Links Management and Technology SpA

Experience in analyzing as-is software systems and ETL flows using PowerCenter. Completed training on Spring Boot for developing modern and scalable backend applications. Backend developer specialized in Spring Boot, with experience in database design, analysis, development, and testing of assigned tasks.

💼
02/2021 - 10/2021

Software developer

Adesso.it (prima era WebScience srl)

Experience in AS-IS and TO-BE analysis, SEO evolution, and website evolution to improve performance and user engagement.

🎓
2018 - 2025

BSc in Computer Science

University of Bari "Aldo Moro

Bachelor's degree in Computer Science, focusing on software engineering, algorithms, and modern development practices.

📚
2013 - 2018

Diploma - Business Information Systems

Commercial Technical Institute of Maglie

Technical diploma in Business Information Systems, combining IT and business management.

Academic Pathway

Bachelor of Science in Computer Science

University of Studies of Bari Aldo Moro - Bari, Italy

Business Information Systems Diploma

Technical Commercial Institute of Maglie — Maglie, Italy

Relevant Projects

Single Repo SSR Portfolio

Angular 21 SSR + Spring Boot 3.4 + FastAPI - 3 microservices, 1404 multilingual articles, 512 open-source dev tools, deployed on Hetzner VPS with Nginx and Cloudflare.

GitHub Wallet — fedcal

ML Service RAG local

FastAPI + RediSearch HNSW + Ollama 3.1:8b on the VPS. Embeds all-MiniLM-L6-v2, re-ranks with cross-encoder, and performs idempotent indexing at boot.

Explore tools

512 Dev Tools are open source.

Payment generators (IBAN MOD-97 ISO 13616), fiscal validators for 50+ countries, payroll calculators for 22 countries, network tools (DNS, SSL, WHOIS). Correct algorithms, over 80% coverage.

Explore Dev Tools

Open Source

  • GitHub Wallet — fedcal
  • IBAN Generator for 50+ countries (MOD-97)
  • Tax Validators - 50+ countries
  • Network tools — DNS, SSL, WHOIS
  • Payroll calculators - 22 countries

Areas of interest

Application verticals with expertise in regulations and business domains.

Healthcare

FHIR R4/R5, EHR (Electronic Health Record), clinical interoperability, health data privacy (GDPR Art. 9)

Fintech

IBAN/BIC validation (23 countries), multi-country tax calculation, payroll calculators and developer tax tools.

ESG / Sustainability

ESG metrics collection and aggregation, structured reporting and dashboards for corporate sustainability transparency.

What you will find here

Technical Articles

Deep-dive on Clean Architecture, Angular performance, Java patterns, SQL optimization, system design, microservices. 618 articles in Italian on development and algorithms. Strictly no hype. For senior devs and architects.

Read the articles

Dev Tools & Algorithms

329 open source tools with correct algorithms: IBAN validator (MOD-97 ISO 13616), Fiscal Code (MOD-26), fiscal validators for 50+ countries, network tools (DNS, SSL, WHOIS). Each tool is accompanied by technical articles that explain the algorithm.

Explore tools

Projects &amp; Architectures

Monorepo microservices (Angular 21 SSR + Spring Boot + FastAPI), clean architecture implementations, ML systems with RAG, E2E case studies. Production-ready code with 80%+ coverage, complete test suite, automated deployment and monitoring.

See projects

Let's talk about it

Have a project in mind? Want to collaborate on an article or a tool? Or just ask a technical question? Write to me directly.