Antonio Bello, iOS Developer in Chrzanow, Poland
Antonio Bello

iOS Developer in Chrzanow, Poland

Member since April 8, 2013
Antonio is a highly experienced (24 years), passionate, self-motivated, result-driven and versatile IT professional specialized in translating business requirements into software solutions, covering the entire software development lifecycle, either autonomously, as part of a team, or as a team leader, using and quickly adapting to any development methodology, programming language, framework, and technology.
Antonio is now available for hire




Chrzanow, Poland



Preferred Environment

Xcode, AppCode, IntelliJ IDEA, Visual Studio

The most amazing...

...service I've built is the best and most used Italian free SMS service, which is capable of sending up to 700,000 SMS per day.


  • Freelance Software Engineer

    2013 - PRESENT
    ByteFactory (
    • Fixed bugs and made improvements on a dating service with clients for both iOS and Android and a Java/Spring-based back end.
    Technologies: Objective C, iOS, Android, Java, JavaScript, Spring, MongoDB
  • Owner, Software Engineer

    2004 - PRESENT
    • Created desktop-based applications to interface with and gather data from a laser-induced plasma spectrometer (LIPS) and an electronic microscope, perform analysis on input data, and submit results to a remote web service. The LIPS application is used to determine the chemical composition of the observed sample, whereas the microscope application reconstructs an interactive 3D model of the analyzed surface.
    • Developed an event organizer to record and report the organizational information related to events, such as races and marathons.
    • Implemented a framework to parse RSS and Atom feeds and import articles into a Goss iCM CMS, designed to be easily extensible to other feed types. Also implemented a bulk user import procedure to scan CSV files, find matches between CSV content and CMS fields, check for data errors, and import users into the CMS.
    • Developed the course administration/management module for an e-learning system built on top of the Kentico CMS.
    • Worked on several projects for a mortgage company to improve internal processing/task automation, many of which were created as proofs of concept and mostly with Google-related technologies.
    • Created an App Engine Java application to pull data from an Encompass database (via MS Access and scheduled upload to/synchronization with Google Data Store) and display detailed employee/branch/company statistics, with automatic page rotation and optimization for full screen LCD TVs.
    • Created a web-based calendar/scheduler to pull data from an Encompass instance and publish details and totals.
    • Developed a web-based application to send SMS messages, manage contacts and group lists, and buy and manage credit.
    • Implemented a Windows mobile order entry application, ported from an existing C++ application.
    • Re-engineered a costs and sales management application for a large Italian paper mill company/group.
    • Developed an online monitor for credit repair software which gathered data from clients and provided real-time statistics.
    • Created a database-driven website to search and filter a mortgage database as well as target loan officers.
    • Developed a web-based interactive door designer which allowed users to design and order doors.
    • Developed a database-driven company website with protected areas for forum discussion and more.
    • Created a job board specifically targeted at game designers and developers for the Canadian market.
    • Developed an ad banner management system consisting of an administrative interface for publishers and advertisers and a banner engine responsible for banner provisioning.
    • Created a website/service for a print, warehousing, and distribution service company which enabled users to order online and track previous/pending orders, and personnel to process orders.
    • Commissioned by the Newcastle Youth Council (UK) to develop a web portal with simple-to-use CMS and able-to-send SMS, ringtones, logos and WAP-push messages.
    • Developed a Windows Mobile order entry application for resellers/distributors of ice cream/frozen products. After initial development and release of version 1.0, the product evolved by gaining hundreds of new features over its 10 years of existence.
    Technologies: Swift, Objective-C, C/C++, C#, Java, JavaScript, CoffeeScript, PHP, Python
  • Lead Engineer, Software Architect

    2019 - 2019
    Toptal Client
    • Worked on an app to share locations with friends, from its conception, contributing to defining the requirements, designing the architecture, and developing the iOS app and the back end.
    • Provided architectural and technical leadership for the mobile development team, coordinating with a remote team and distributing responsibilities.
    • Drew together requirements on project needs from various stakeholders and cross-functional team members.
    • Learned the Go language while implementing the back end.
    Technologies: iOS, Swift, Go, Google Maps, Firebase, Postgres, PostGIS
  • Senior iOS Engineer

    2018 - 2019
    Toptal Client
    • Worked on an app to help people quit smoking.
    • Provided generic maintenance for the application, ensuring the best performance, quality, and responsiveness.
    Technologies: iOS, Swift
  • Senior iOS Engineer

    2018 - 2018
    Toptal Client
    • Joined a team to develop a service for finding and instantly hiring body guards, conceptually similar to Uber.
    Technologies: iOS, Swift
  • Senior iOS Engineer

    2017 - 2018
    Toptal Client
    • Worked on a club finder social app.
    • Joined the project to complete the development of an app, to discover clubs around you.
    Technologies: iOS, Swift, Mapbox, Core Location
  • Software Engineer

    2017 - 2017
    Apps for Gaps (via Toptal)
    • Worked on an app to discover stores around you with your favorite brands.
    Technologies: iOS, Swift, MapKit
  • Software Engineer, iOS Developer

    2017 - 2017
    ILF Mobile Apps (, via Toptal)
    • Worked on a private messaging app (voice and text) and secure vault for images and videos.
    Technologies: iOS, Swift, VoIP, Encryption, Messaging
  • Software Engineer

    2017 - 2017
    Brave (, via Toptal)
    • Maintained an existing app (not yet launched) for connecting people that need help with people who can volunteer to provide it.
    • Fixed bugs on the app.
    Technologies: iOS, Node.js
  • iOS developer

    2017 - 2017
    MindTrust Labs (, via Toptal)
    • Worked on a medical app to track sensorial and motor activities for child patients.
    Technologies: iOS, Swift
  • Software Engineer

    2017 - 2017
    Social Scan (via Toptal)
    • Maintained the app by adding new features and fixing some problems.
    Technologies: Swift, iOS
  • iOS Software Engineer

    2016 - 2016
    Contra (; via Toptal)
    • Contributed to Contra, a social opinions platform.
    • Helped improve the app, add new features, and fix bugs.
    Technologies: iOS, Objective-C, Node.js, JavaScript
  • iOS Software Engineer

    2016 - 2016
    Keepy (; via Toptal)
    • Contributed to Keepy, a kids’ artwork, schoolwork, and mementos organizer.
    • Helped improve the app and fix some bugs.
    Technologies: iOS, Swift, Objective-C, Node.js, JavaScript, MySQL
  • iOS Software Engineer

    2016 - 2016
    Blue Lasso (; via Toptal)
    • Contributed to Blue Lasso, an iPad client for a training and advisory service, focusing on projects, people, and planning tools.
    • Added new features and fixed bugs.
    Technologies: iOS, Swift, iPad
  • Freelance Software Engineer

    2014 - 2016 (
    • Implemented a task/goal tracking service.
    • Worked with beacons to implement basic indoor positioning.
    • Created a watchOS app to start/stop trackers, linked to the iOS app.
    • Designed and implemented a Node.js back-end, exposing REST APIs.
    • Developed the iOS app.
    Technologies: iOS, tvOS, watchOS, Node.js, MongoDB, Swift, Objective-C, CoffeeScript, Beacons
  • iOS Software Engineer

    2015 - 2015
    RAD Fitkey (; via Toptal)
    • Contributed to RAD Fitkey, a body measurement app to create a body profile with just three pictures.
    • Joined the team for bug fixing and for adding new features.
    Technologies: iOS, Swift
  • iOS Software Engineer

    2015 - 2015
    Crowdservice (; via Toptal)
    • Contributed to Crowdservice, a platform for customers to post tasks where providers can bid and do the task when selected.
    • Helped fix bugs and add new features.
    Technologies: iOS, Objective-C, PHP
  • Freelance Software Engineer

    2015 - 2015
    PooledHouse (; via Toptal)
    • Designed the architecture and developed an iOS app for a service to track jobs, tips, and earnings.
    Technologies: iOS, Swift,, Google Maps, JavaScript
  • CTO, Software Engineer

    2012 - 2015
    Ubersimple, LLC (
    • Designed the high-level architecture of a mobile service used to share lists of apps and digital business cards.
    • Implemented the server in Node.js, using both JavaScript and CoffeeScript.
    • Implemented the native iOS client app, written in Objective-C and Swift.
    • Implemented the native Android client app, written in Java.
    Technologies: Java, Objective-C, JavaScript, CoffeeScript
  • Freelance Software Engineer

    2014 - 2014
    Burnbook (via Toptal)
    • Designed the architecture and developed the iOS app for anonymous posting at Mashable (
    • Began development in Objective-C, later progressively replaced by Swift for new features.
    Technologies: iOS, Objective C, Swift,, JavaScript
  • Freelance Software Engineer

    2013 - 2013
    • Created new features and fixed bugs on a previously developed app, whose purpose is to promote a healthy lifestyle.
    Technologies: Objective C, iOS, Node.js, JavaScript
  • Analyst, Lead Developer

    2003 - 2003
    AG Team S.r.l. (
    • Redesigned an existing COBOL ERP application in Java/J2EE.
    • Performed maintenance on a Windows CE order entry application.
    Technologies: Java, C++
  • Project Leader, Analyst, Senior Developer

    1997 - 2002
    Ksolutions S.p.A.
    • Created the first and most popular Italian free SMS service (Kataweb FreeSMS).
    • Involved in strategic/pilot workforce management projects using mobile technologies (commissioned by the largest Italian mobile operator and railway company).
    • Designed and developed applications on a variety of mobile platforms, such as Apple Newton, Palm Pilot, and Windows CE.
    • Designed and implemented an SMS engine to target Windows CE platforms, capable of sending and receiving SMS using a GSM card/mobile phone connected to the device.
    Technologies: C/C++, Java, Pascal, SQL, PL/SQL, HTML, XML, NewtonScript
  • IT Consultant

    1996 - 1996
    Zappalà S.p.A.
    • Designed and implemented a controller for product delivery automation, identifying products by reading bar codes from a conveyor belt, assigning a client/destination basing on an orders database, and routing them accordingly.
    Technologies: C++


  • Book: ARKit by Tutorials (Other amazing things)

    As a co-author, I wrote five chapters guiding the reader into developing an ARKit app to create an interactive billboard, to detect and track images and to detect 3D objects.

  • Book: SwiftUI by Tutorials (Other amazing things)

    As a co-author, I wrote three chapters showcasing to the reader the SwiftUI components to build declarative user interfaces.

  • Book: iOS 11 by Tutorials (Other amazing things)

    iOS 11 by Tutorials is a tutorial-based book that teaches how to use the new APIs introduced in iOS 11.

    I contributed to this book as a technical editor.

  • Book: watchOS by Tutorials, Second and Third Editions (Other amazing things)

    watchOS by Tutorials is a tutorial-based book that teaches how to make apps for the Apple Watch.

    I contributed to this book as a technical reviewer.

  • Author and Tech Editor at (Other amazing things) is probably the most used resource for tutorials, articles, and books related to iOS, and more generally the Apple ecosystem.

    I write about programming, freelancing, and working remotely.

  • Music Production (Other amazing things)

    I enjoy composing songs, and everything related to producing, mixing, and mastering.

    Linked here is my growing collection of song excerpts on Soundcloud.

  • Swift Essentials, Second Edition (Other amazing things)

    A fast-paced guide that provides an overview of Swift programming

    I contributed to this book as a technical reviewer.

  • Game Development with Swift (Other amazing things)

    I contributed to this book as a technical reviewer.

  • 2016 Blue Lasso (Development)

    The Blue Lasso app supports the training and delivery of services provided by Blue Lasso. Clients use the app in support of the training and advisory. The SaaS-based service engages three intuitive tools focusing on projects, people, and planning.

  • 2016 (Development)

    Task/goal tracking service.

  • 2015 RAD Fitkey (Development)

    Body measurement app to create a universal body profile with just three pictures.

  • 2014 VGL (iOS) (Development)
  • 2015 AppPack (iOS) (Development)

    Application to share and recommend other applications, links, and videos as well as provide a digital business card service.

  • 2015 AppPack (Android) (Development)

    Application to share and recommend other applications, links, and videos as well as provide a digital business card service.

  • 2016 Keepy (Development)

    Keepy is a kids’ artwork, schoolwork, and memento organizer.

  • 2016 Contra (Development)
  • 2016 Crowdservice (Development)

    Service for customers to post tasks, where providers can bid on and do the task when selected.

  • 2015 Pooled House (Development)

    Service to track jobs, tips, and earnings.

  • 2015 Ubliette (Development)

    Fashion browsing and shopping.

    I worked on bug fixes and improvements.

  • 2014 Burnbook (via Toptal) (Development)

    Anonymous posting app, allowing users to post anonymous text and audio messages as well as videos.

  • Apple Watch in a Nutshell: A Feature Introduction for iOS Developers (Publication)
    Apple has released a fully functional WatchKit and SDK that enables iOS developers with all the tools to start building their Apple Watch applications. This article provides quick overview of the Apple Watch functionalities from a developers perspective.
  • iOS User Interfaces: Storyboards vs. NIBs vs. Custom Code (Publication)
    I often hear iOS developers ask some variant of the same key question: "What's the best way to develop a UI in iOS: through Storyboards, NIBs, or code?" Answers to this question, explicitly or implicitly, tend to assume that there's a mutually exclusive choice to be made, one that is often addressed upfront, before development. I'm of the opinion that there's no single choice to be made. Rather, each option has its strengths and weaknesses—and there's no need to use any one of them in isolation.
  • Toptal Mentor
    Antonio is a mentor in the Toptal Global Mentor’s Program. This program is a partnership between Toptal and General Assembly to provide high quality mentorship for students from minority and low income backgrounds who are looking to begin their careers as professional software engineers. Antonio shows commitment to diversity in tech by mentoring a General Assembly student every week for a year, covering everything from coding tips and tricks to advice on making it in the industry.


  • Languages

    C, Java, C#, SQL, Swift, Objective-C, HTML, CoffeeScript, JavaScript, C++, Go
  • Frameworks

    iOS SDK, ARKit, .NET, ASP.NET, Android SDK
  • Tools

  • Paradigms

    Object-oriented Programming (OOP), App Development, Agile Software Development, Test-driven Development (TDD)
  • Platforms

    iOS, watchOS, Java EE, Android, tvOS, Oracle
  • Other

  • Libraries/APIs

    Node.js, Microsoft Foundation Class Library (MFC), OpenGL, jQuery, jQuery UI
  • Storage

    MySQL, Microsoft SQL Server, MongoDB, PostgreSQL


  • (Not completed) Bachelor's degree in Computer Science
    1988 - 1995
    University of Pisa - Pisa, Italy

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