Hi! I'm

Federico Calò

Software Developer | Technical Writer

I create modern web applications and custom digital tools to help businesses grow through technological innovation. My passion is combining computer science and economics to generate real value.

Contact Me

About Me

My passion for computer science was born at the Technical Commercial Institute of Maglie, where I discovered the power of programming and the fascination of creating digital solutions. From the start, I understood that computer science was not just code, but an extraordinary tool for turning ideas into reality.

During my studies in Business Information Systems, I began to interweave computer science and economics, understanding how technology can be the engine of growth for any business. This vision accompanied me to the University of Bari, where I obtained my degree in Computer Science, deepening my technical skills and passion for software development.

Today I put this experience at the service of businesses, professionals and startups, creating tailor-made digital solutions that automate processes, optimize resources and open new business opportunities. Because true innovation begins when technology meets the real needs of people.

My Skills

Data Analysis & Predictive Models

I transform data into strategic insights with in-depth analysis and predictive models for informed decisions

Process Automation

I create custom tools that automate repetitive operations and free up time for value-added activities

Custom Systems

I develop tailor-made software systems, from platform integrations to customized dashboards

const federico = {
  nome: "Federico Calò",
  ruolo: "Sviluppatore Software",
  città: "Bari, Italia",
  missione: "Aiutare attraverso l'informatica",
  passioni: [
    "Codice Pulito",
    "Innovazione",
    "Crescita Continua"
  ]
};

La Mia Missione

Credo fermamente che l'informatica sia lo strumento più potente per trasformare le idee in realtà e migliorare la vita delle persone.

🚀

Democratizzare la Tecnologia

La mia missione è rendere l'informatica accessibile a tutti: dalle piccole imprese locali alle startup innovative, fino ai professionisti che vogliono digitalizzare la propria attività. Ogni realtà merita di sfruttare le potenzialità del digitale.

💡

Unire Informatica ed Economia

Non è solo questione di scrivere codice: è capire come la tecnologia possa generare valore reale. Intrecciando competenze informatiche e visione economica, aiuto le attività a crescere, ottimizzare processi e raggiungere nuovi traguardi di efficienza e redditività.

🎯

Creare Soluzioni su Misura

Ogni attività è unica, e così devono esserlo le soluzioni. Sviluppo strumenti personalizzati che rispondono alle esigenze specifiche di ciascun cliente, automatizzando processi ripetitivi e liberando tempo per ciò che conta davvero: far crescere il business.

Trasforma la Tua Attività con la Tecnologia

December 2024

View

Master SQL

RoadMap.sh

Novembre 2024

View

Oracle Certified Foundations Associate

Oracle

October 2024

View

People Leadership Credential

Connect

Settembre 2024

💻 Languages & Technologies

☕Java

🐍Python

📜JavaScript

🅰️Angular

⚛️React

🔷TypeScript

🗄️SQL

🐘PHP

🎨CSS/SCSS

🔧Node.js

🐳Docker

🌿Git

💼

12/2024 - Presente

Custom Software Engineering Analyst

Accenture

Bari, Puglia, Italia · Ibrida Analisi e sviluppo di sistemi informatici attraverso l'utilizzo di Java e Quarkus in Health and Public Sector. Formazione continua su tecnologie moderne per la creazione di soluzioni software personalizzate ed efficienti e sugli agenti.

💼

06/2022 - 12/2024

Analista software e Back End Developer Associate Consultant

Links Management and Technology SpA

Esperienza nell'analisi di sistemi software as-is e flussi ETL utilizzando PowerCenter. Formazione completata su Spring Boot per lo sviluppo di applicazioni backend moderne e scalabili. Sviluppatore Backend specializzato in Spring Boot, con esperienza in progettazione di database, analisi, sviluppo e testing dei task assegnati.

💼

02/2021 - 10/2021

Programmatore software

Adesso.it (prima era WebScience srl)

Esperienza nell'analisi AS-IS e TO-BE, evoluzioni SEO ed evoluzioni website per migliorare le performance e l'engagement degli utenti.

🎓

2018 - 2025

Laurea in Informatica

Università degli Studi di Bari Aldo Moro

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

📚

2013 - 2018

Diploma - Sistemi Informativi Aziendali

Istituto Tecnico Commerciale di Maglie

Technical diploma specializing in Business Information Systems, combining IT knowledge with business management.

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Integration Testing and Flutter DevTools: End-to-End on Real Device

Integration tests are the most realistic level of Flutter testing: they run on physical device or emulator, drive the app as a real user would and verify complete flows from UI input to backend response. Unlike test widgets that isolate a single component, integration tests traverse the entire stack application — navigation, state management, HTTP, local storage.

In this article we build a complete integration test pipeline: we write the tests with the package integration_test, we run them locally on the emulator, we automate them on GitHub Actions and finally run them on real physical devices with Firebase Test Lab. We use Flutter DevTools to analyze memory and CPU during execution, identifying performance regressions before deployment.

What You Will Learn

Difference between unit tests, widget tests and integration tests in Flutter
Package setup integration_test and test file structure
Writing E2E tests with IntegrationTestWidgetsFlutterBinding
Use of find, tap, enterText e pumpAndSettle
Flutter DevTools: Memory Profiler, CPU Profiler and Network tab
GitHub Actions: CI/CD pipeline for integration tests on emulator
Firebase Test Lab: Running on an array of physical devices
Mocking strategies for isolating the backend in E2E testing

The Test Pyramid in Flutter

Before writing integration tests, it is essential to understand where they fit in Flutter testing pyramid and what their cost/benefit is compared to the other levels.

Type	Speed	Loyalty	Maintenance	When to use them
Unit Tests	~1ms per test	Low (isolated logic)	Minimal	Business logic, repository, utils
Widget Tests	~50ms per test	Medium (UI without device)	Average	UI components, interactions
Integration Test	~30s per test	High (real device)	High	Critical flows, E2E regression

The rule of thumb: 70% unit tests, 20% widget tests, 10% integration tests. The tests of integration are valuable but expensive — use them for critical business flows (login, checkout, onboarding) where a regression causes real harm.

Project Setup

# pubspec.yaml: dipendenze per integration testing

dependencies:
  flutter:
    sdk: flutter
  integration_test:
    sdk: flutter  # gia incluso nell'SDK Flutter

dev_dependencies:
  flutter_test:
    sdk: flutter
  integration_test:
    sdk: flutter
  mocktail: ^1.0.4         # per mock degli HTTP client
  fake_async: ^1.3.1       # per controllare il tempo nei test

# Struttura directory raccomandata
# test/                    unit test e widget test
# integration_test/        integration test
#   app_test.dart
#   flows/
#     auth_flow_test.dart
#     checkout_flow_test.dart
#   helpers/
#     test_helpers.dart

The First Integration Test

The binding for integration tests is different from that of widget tests: IntegrationTestWidgetsFlutterBinding.ensureInitialized() initialize the binding that communicates with the native device and enables the collection of performance metrics.

// integration_test/app_test.dart

import 'package:flutter_test/flutter_test.dart';
import 'package:integration_test/integration_test.dart';
import 'package:my_app/main.dart' as app;

void main() {
  // OBBLIGATORIO: inizializza il binding integration test
  final binding = IntegrationTestWidgetsFlutterBinding.ensureInitialized();

  group('App Integration Tests', () {
    testWidgets('App si avvia e mostra la home page', (tester) async {
      // Avvia l'app completa (non un widget isolato)
      app.main();
      await tester.pumpAndSettle(); // Aspetta che tutte le animazioni finiscano

      // Verifica che la home page sia visibile
      expect(find.text('Benvenuto'), findsOneWidget);
      expect(find.byKey(const Key('home_page')), findsOneWidget);
    });

    testWidgets('Navigazione tra le tab funziona', (tester) async {
      app.main();
      await tester.pumpAndSettle();

      // Tap sulla tab Profile
      await tester.tap(find.byKey(const Key('nav_profile')));
      await tester.pumpAndSettle();

      // Verifica che la pagina profilo sia caricata
      expect(find.byKey(const Key('profile_page')), findsOneWidget);

      // Torna alla Home
      await tester.tap(find.byKey(const Key('nav_home')));
      await tester.pumpAndSettle();

      expect(find.byKey(const Key('home_page')), findsOneWidget);
    });
  });
}

Testing a Complete Authentication Flow

A login flow is the ideal candidate for integration testing: it engages UI, validation, HTTP calling, token storage and post-login navigation.

// integration_test/flows/auth_flow_test.dart

import 'package:flutter_test/flutter_test.dart';
import 'package:integration_test/integration_test.dart';
import 'package:my_app/main.dart' as app;

void main() {
  IntegrationTestWidgetsFlutterBinding.ensureInitialized();

  group('Auth Flow', () {
    testWidgets('Login con credenziali valide naviga alla home', (tester) async {
      app.main();
      await tester.pumpAndSettle();

      // Trova e compila il campo email
      final emailField = find.byKey(const Key('email_field'));
      expect(emailField, findsOneWidget);
      await tester.tap(emailField);
      await tester.enterText(emailField, 'test@example.com');

      // Compila il campo password
      final passwordField = find.byKey(const Key('password_field'));
      await tester.tap(passwordField);
      await tester.enterText(passwordField, 'password123');

      // Chiudi la tastiera
      await tester.testTextInput.receiveAction(TextInputAction.done);
      await tester.pumpAndSettle();

      // Tap sul pulsante di login
      await tester.tap(find.byKey(const Key('login_button')));

      // Aspetta che il login HTTP completi (max 5 secondi)
      await tester.pumpAndSettle(const Duration(seconds: 5));

      // Verifica redirect alla home page
      expect(find.byKey(const Key('home_page')), findsOneWidget);
      expect(find.byKey(const Key('login_page')), findsNothing);
    });

    testWidgets('Login con credenziali errate mostra errore', (tester) async {
      app.main();
      await tester.pumpAndSettle();

      await tester.enterText(
        find.byKey(const Key('email_field')),
        'wrong@example.com',
      );
      await tester.enterText(
        find.byKey(const Key('password_field')),
        'wrongpassword',
      );
      await tester.tap(find.byKey(const Key('login_button')));
      await tester.pumpAndSettle(const Duration(seconds: 5));

      // Deve apparire il messaggio di errore
      expect(find.text('Credenziali non valide'), findsOneWidget);
      // Deve rimanere sulla login page
      expect(find.byKey(const Key('login_page')), findsOneWidget);
    });

    testWidgets('Validazione form: email non valida blocca il submit', (tester) async {
      app.main();
      await tester.pumpAndSettle();

      await tester.enterText(
        find.byKey(const Key('email_field')),
        'email-non-valida',
      );
      await tester.tap(find.byKey(const Key('login_button')));
      await tester.pumpAndSettle();

      // Errore di validazione visibile (no HTTP call effettuata)
      expect(find.text('Inserisci un\'email valida'), findsOneWidget);
    });
  });
}

Collection of Performance Metrics

Integration testing is not just functional correctness: the binding integration test Allows you to collect frame timing, memory and rendering metrics at runtime of the test, producing a JSON report that can be parsed in CI.

// integration_test/performance_test.dart

import 'package:flutter_test/flutter_test.dart';
import 'package:integration_test/integration_test.dart';
import 'package:my_app/main.dart' as app;

void main() {
  final binding = IntegrationTestWidgetsFlutterBinding.ensureInitialized();

  testWidgets('Scrolling della lista prodotti: performance test', (tester) async {
    app.main();
    await tester.pumpAndSettle();

    // Naviga alla lista prodotti
    await tester.tap(find.byKey(const Key('nav_products')));
    await tester.pumpAndSettle();

    // Raccoglie metriche durante il scroll
    await binding.watchPerformance(() async {
      // Scroll veloce per 5 paginate
      for (int i = 0; i < 5; i++) {
        await tester.fling(
          find.byKey(const Key('products_list')),
          const Offset(0, -500),
          3000, // velocita pixels/secondo
        );
        await tester.pumpAndSettle();
      }
    },
    reportKey: 'products_scroll_perf');

    // Le metriche vengono salvate automaticamente in un file JSON
    // Accessibile via: flutter drive --profile
  });
}

// Comando per raccogliere metriche in modalita profile:
// flutter drive \
//   --driver=test_driver/integration_test.dart \
//   --target=integration_test/performance_test.dart \
//   --profile

Flutter DevTools: Deep Profiling

Flutter DevTools is a suite of diagnostic tools accessible via browser while the app is running in debug or profile mode. The most useful tabs to identify performance problems are the Performance tab (frame timing), the Memory tab (heap allocation) and the Network tab (HTTP latency).

# Avviare DevTools durante un integration test

# 1. Lancia l'app in modalita debug su emulatore
flutter run --debug

# 2. Apri DevTools (automaticamente o manualmente)
flutter pub global run devtools

# 3. Oppure direttamente da VS Code / Android Studio
# View > Command Palette > Flutter: Open DevTools

# Performance tab: comandi utili
# - "Record" per catturare una sessione
# - "Enhance Tracing" per shader e build details
# - Filtra per "Janky frames" (rosso = sopra 16ms budget)

# Memory tab: identificare memory leak
# - "GC" button: forza garbage collection
# - "Snapshot" prima e dopo un'operazione
# - Confronta gli heap dump per trovare oggetti non rilasciati

# Network tab
# - Mostra tutte le richieste HTTP/HTTPS
# - Timing breakdown: DNS, connect, send, wait, receive
# - Filtro per URI pattern

Memory Leak Pattern Common in Flutter

The most common memory leak in integration tests (and in production) isAnimationController not willing: A controller created in initState without the corresponding one dispose() accumulates listeners and is never released by the garbage collector. Flutter DevTools Memory tab identifies it as an object with retaining path to the root.

GitHub Actions: CI/CD Pipeline for Integration Testing

Running integration tests in CI requires an Android emulator or an iOS simulator. Here is a complete GitHub Actions setup optimized for fast build times.

# .github/workflows/integration-tests.yml

name: Integration Tests

on:
  push:
    branches: [main, develop]
  pull_request:
    branches: [main]

jobs:
  integration-tests-android:
    runs-on: ubuntu-latest
    timeout-minutes: 30

    steps:
      - name: Checkout repository
        uses: actions/checkout@v4

      - name: Setup Java (richiesto per emulatore Android)
        uses: actions/setup-java@v4
        with:
          java-version: '17'
          distribution: 'temurin'

      - name: Setup Flutter
        uses: subosito/flutter-action@v2
        with:
          flutter-version: '3.27.0'
          channel: 'stable'
          cache: true  # cache delle dipendenze Flutter

      - name: Install dependencies
        run: flutter pub get

      - name: Enable KVM (accelerazione hardware emulatore)
        run: |
          echo 'KERNEL=="kvm", GROUP="kvm", MODE="0666", OPTIONS+="static_node=kvm"' \
            | sudo tee /etc/udev/rules.d/99-kvm4all.rules
          sudo udevadm control --reload-rules
          sudo udevadm trigger --name-match=kvm

      - name: Avvia emulatore Android
        uses: reactivecircus/android-emulator-runner@v2
        with:
          api-level: 33
          arch: x86_64
          profile: Nexus 6
          avd-name: integration_test_avd
          emulator-options: -no-snapshot-save -no-window -gpu swiftshader_indirect -noaudio -no-boot-anim
          disable-animations: true  # disabilita animazioni per test piu veloci
          script: |
            flutter test integration_test/ \
              --flavor development \
              -d emulator-5554 \
              --dart-define=ENVIRONMENT=test

      - name: Upload test results
        if: always()
        uses: actions/upload-artifact@v4
        with:
          name: integration-test-results
          path: build/integration_test_results/

Firebase Test Lab: Physical Device Matrix

GitHub Actions with Emulators covers basic testing, but physical devices they have real hardware differences (GPU, sensors, OEM Android variants) that the emulator does not play. Firebase Test Lab offers a fleet of devices physical files on which to run the app.

# Preparazione dell'APK per Firebase Test Lab

# 1. Build dell'app e del test APK separati
flutter build apk --debug --target-platform android-arm64
flutter build apk --debug \
  --target=integration_test/app_test.dart \
  --target-platform android-arm64

# 2. Upload e avvio del test su Firebase Test Lab via gcloud CLI
gcloud firebase test android run \
  --type instrumentation \
  --app build/app/outputs/apk/debug/app-debug.apk \
  --test build/app/outputs/apk/debug/app-debug-androidTest.apk \
  --device model=Pixel6,version=33,locale=it,orientation=portrait \
  --device model=SamsungS22,version=32,locale=it,orientation=portrait \
  --device model=OnePlus9,version=31,locale=it,orientation=portrait \
  --timeout 5m \
  --results-bucket=gs://my-project-test-results \
  --results-dir=integration_tests/$(date +%Y%m%d_%H%M%S)

# Integrazione Firebase Test Lab in GitHub Actions

- name: Authenticate Google Cloud
  uses: google-github-actions/auth@v2
  with:
    credentials_json: ${{ secrets.GCP_CREDENTIALS }}

- name: Setup gcloud CLI
  uses: google-github-actions/setup-gcloud@v2

- name: Build test APKs
  run: |
    flutter build apk --debug
    flutter build apk --debug \
      --target=integration_test/app_test.dart

- name: Run tests on Firebase Test Lab
  run: |
    gcloud firebase test android run \
      --type instrumentation \
      --app build/app/outputs/apk/debug/app-debug.apk \
      --test build/app/outputs/apk/debug/app-debug-androidTest.apk \
      --device model=Pixel6,version=33,locale=it,orientation=portrait \
      --timeout 5m \
      --results-bucket=gs://my-app-test-results

Mocking Strategy for Reliable E2E Tests

Tests that depend on a real backend are fragile: the server can be down, data can change, latency varies. The best strategy for testing integration and use a mock local server (as mockito or a fake HTTP server) configurable via --dart-define.

# main.dart: configurazione per ambiente test

// main.dart
void main() {
  // Legge la variabile di ambiente iniettata dalla CI
  const environment = String.fromEnvironment(
    'ENVIRONMENT',
    defaultValue: 'production',
  );

  if (environment == 'test') {
    // Usa il mock HTTP client per i test di integrazione
    HttpOverrides.global = _MockHttpOverrides();
  }

  runApp(
    ProviderScope(
      overrides: environment == 'test'
          ? [
              // Override Riverpod provider con il mock repository
              apiClientProvider.overrideWithValue(MockApiClient()),
            ]
          : [],
      child: const MyApp(),
    ),
  );
}

class _MockHttpOverrides extends HttpOverrides {
  @override
  HttpClient createHttpClient(SecurityContext? context) {
    // Intercetta tutte le richieste HTTP e restituisce dati fissi
    return MockHttpClient();
  }
}

Best Practices for Stable Integration Tests

Use Explicit Keys: every interactive widget must have a Key constant to make it findable in tests in a stable way.
You prefer pumpAndSettle a pump: pumpAndSettle wait for all the hanging animations and frames end, reducing flaky tests due to timing.
Explicit timeouts: USA pumpAndSettle(Duration(seconds: 5)) for asynchronous operations instead of the default infinite timeout.
Resetting state between tests: USA tearDown for clean SharedPreferences, local databases and authentication tokens.
Disable animations: in US CI pipelines --no-enable-impeller and disable animations to speed up execution by 40%.

Conclusions

Integration tests are the last line of defense before deployment to production: they capture regressions that escape unit tests because they emerge from interaction between real components on real hardware. The cost is high — 30-60 seconds per test, setup complexity, ongoing maintenance — but for critical business flows the ROI is indisputable.

The combination of GitHub Actions for quick feedback on every PR and Firebase Test Lab for coverage across heterogeneous physical devices creates a safety net solid that allows you to deploy with confidence. Flutter DevTools completes the picture providing visibility into performance at runtime, transforming tests integration from simple correctness checks to monitoring tools quality of user experience.