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Josip Petrić, Software Developer in Zagreb, Croatia
Josip Petrić

Software Developer in Zagreb, Croatia

Member since May 31, 2016
As a software engineer with years of experience, Josip has developed a keen sense for building scalable, maintainable, and user-friendly applications. His platform of choice is iOS for which he has designed and developed a wide range of applications, from simple ones to complex, large-scale applications. Josip is a proven team leader and a team player with exemplary communication and social skills.
Josip is now available for hire



  • Object-oriented Programming (OOP), 9 years
  • Xcode, 7 years
  • iOS, 7 years
  • Objective-C, 6 years
  • Git, 5 years
  • Swift, 3 years
Zagreb, Croatia



Preferred Environment

iOS, Xcode, Git, Swift, Objective-C

The most amazing... I've created was Comic Battle, a fast-paced multiplayer game for iOS where I was the only mobile developer.


  • Co-founder | Lead iOS Developer

    2015 - PRESENT
    Bit Forest
    • Created, as the only iOS developer, a complex real-time multiplayer iOS game, Comic Battle, from scratch.
    • Developed a large-scale iOS mobile application for a taxi service. Application features: live vehicle tracking, customizable dispatch zones, and automatic payment through the application.
    • Created a set of features for a mobile travel guide for sailors in Croatia, Slovenia, and Greece.
    • Consulted on the introduction of a quality insurance system for mobile development projects. The QA system described every project step, from requirements and mockups to prototyping and integration testing.
    • Led a small mobile development team.
    Technologies: iOS, Objective-C, Swift, Core Animation, Core Data, Git, Facebook API, Twitter API, Core Location, Google Maps, Google Places, Payment Gateways, In-App Purchases, Apple WatchKit
  • iOS Developer

    2018 - 2019
    OverUnder (via Toptal)
    • Built and maintained a streak-style contest application where users can win cash prizes by predicting the over-under on featured sports events.
    • Developed an application using protocol-oriented MVVM architecture with a clear separation of concerns between modules.
    • Created a custom chat functionality which allows users to communicate and to receive real-time sport event updates.
    • Implemented a notification content extension to customize the appearance of push notifications.
    • Helped to identify and implement key analytic events and funnels.
    • Added support for mobile ads.
    Technologies: Swift, CoreData, Xcode, Instruments, Firebase, Fabric, Google Mobile Ads, Instabug
  • iOS Developer

    2017 - 2017
    Lawyerer (via Toptal)
    • Developed an app where the users can create binding and non-binding agreements, communicate and negotiate terms with a counterparty, and at the end sign the agreement.
    • Worked as the iOS developer while collaborating with a designer, back-end developer, web front-end developer, and a project manager.
    • Managed and was responsible for the whole iOS app development process: from managing a Git repository, making key architecture decisions, testing, and test flight releases.
    • Developed a specific and clean flow concerning the agreement terms negotiation and communication between the counterparties with commenting, agreement locking, editing, and notification functionalities.
    Technologies: iOS, Swift, Push Notifications, Core Animation, REST, Git
  • Senior iOS Developer

    2017 - 2017
    Adforprize (via Toptal)
    • Developed Adforprize—a platform where users can express themselves through creative ads. Companies posts prizes which are rewarded to users who make the best ads for their campaign.
    • Refactored an existing application and resolved a number of issues and memory leaks.
    • Implemented and worked on a custom video feed, in-app chat, advanced video editor (adding/removing video segments, inserting GIFs, adding soundtracks), and various custom UI components (Adforprize demo: ).
    • Worked closely with the founder and other team members.
    • Attended daily standups and proposed new features, solutions, and iOS best practices.
    Technologies: iOS, Swift 3, AVKit, Core Animation, Firebase, Git, REST
  • iOS Developer

    2016 - 2017
    NimbleRx (via Toptal)
    • Developed a set of three iOS applications.
    • Supported and added new features to the NimbleRx application.
    • Created the app, NimbleRx which keeps track of users prescriptions; a user can order prescription refills, track it on the map and pay it using the app.
    • Led the iOS development on the NimbleMD application.
    • Created the NimbleRx marketing iPad application.
    • Developed applications fully in Swift by utilizing protocol-oriented programming concepts.
    Technologies: iOS, Swift, Crashlytics, Amplitude, Git, Core Animation, MapKit
  • Lead iOS Developer

    2016 - 2016
    Proballers (via Toptal)
    • Worked as the sole iOS engineer on the project closely collaborating with back-end engineering and project management.
    • Developed the Proballers' application from scratch and released it to the App Store in 6 weeks.
    • Supported and guided the set up of a source code repository, Apple developer accounts, in-app purchases, analytics, crash reporting, and releasing the app on Test Flight and in the App Store.
    Technologies: Swift, iOS, Git, Crashlytics, AV Foundation, Answers, Facebook API, Twitter API
  • Software Engineer | Lead iOS Developer

    2013 - 2015
    Amphinicy Technologies
    • Implemented a set of mobile (iOS and Android) applications for use by operatives of the rapid response team for disaster relief and humanitarian operations.
    • Developed a mobile application for configuring satellite antenna (Azimuth, Elevation, and Skew Angles) for appropriate geosynchronous satellite through an augmented reality interface.
    • Participated in the whole software development process, from the requirements-and-design phase to testing, integration, and communication with a client.
    • Worked as the technical interviewer of new iOS developer applicants.
    • Led a small team.
    Technologies: iOS, Objective-C, Swift, Android, Appcelerator
  • Junior Software Engineer

    2011 - 2012
    Amphinicy Technologies
    • Developed for Amphinicy Technologies—the world’s leading software provider for companies operating in the satellite industry.
    • Developed the Java back-end for a large in-house CMS product.
    • Implemented Android and iOS mobile clients (EPUB and PDF reader) for the in-house CMS.
    • Developed the mobile CMS client by customizing, configuring, and adding features to an existing RMSDK client application.
    • Collaborated and communicated with international clients.
    • Worked in both local and distributed teams.
    Technologies: iOS, Objective-C, Android, Java, Flex


  • Define It (Development)

    Define It is a minimalist vocabulary builder application featuring speech recognition and optical character recognition. Users can create their vocabulary and expand it by playing various quick and fun word games.

    • Built entirely in Swift using clean MVVM architecture and protocol-oriented programming concepts.
    • Implemented speech recognition and optical character recognition (text recognition from image) features.
    • Added the Today extension (widget), WatchKit extension.

  • Proballers (Development)

    Proballers is the first app connecting basketball players to their fans, all over the world. Professional players engage with their fans by publishing various content on their timeline. Fans can interact with their favorite players and browse through various statistics presented in a user friendly way.

    • Fully developed in Swift in a modular and reusable fashion utilizing custom controls and protocol-oriented concepts.
    • Implemented Auto-renewable subscriptions system, Social networks integration, Facebook-like timeline, and player verification system via video recording.

  • Comic Battle (Development)

    A fast-paced, multiplayer iOS game where players train a team of fighters and challenge other players worldwide to a real-time duels.

    • Developed using Cocos2d-iPhone and native UIKit components.
    • Implemented a custom network communication library using TCP stream and TCP socket connection to avoid unnecessary overhead in communication with the server.
    • Implemented a connection error handling mechanism for user friendly re-connection and state perseverance, which is especially important when the player is in the middle of a duel with another player.
    • Created a modular architecture which makes it easy and painless to add new game resources (new characters, items, skills or side effects).
    • User analytics, crash reporting, easy content adding mechanism
    • Was the only mobile developer on the game and product manager.

  • mySea (Development)

    mySea is a an interactive cruising guide for Greece, Croatia and Turkey (Mediterranean coast) as well as an online reservation system for berths.

    • Added a set of new features: berth search, booking and payment, boats configuration and validation manager, user tutorial and booking history.
    • Payment gateway integration.

  • Set of Utility Mobile Applications for Field Operatives (Development)

    • Implemented the iOS and Android mobile applications for configuring solar panels to achieve maximum usability for a specified period of time.
    • Implemented iOS and Android applications for configuring satellite antenna to point to a specified geosynchronous satellite.
    • Configured, rebranded, and added additional features to a VoIP application to meet project requirements and to use specific audio codecs.
    • Gained knowledge and experience in VoIP technology.
    • Utilized device sensors to calculate appropriate azimuth, elevation and skew angles required to setup satellite antennas.

  • How to Write Automated Tests for iOS (Publication)
    In this tutorial, you will learn how automated testing works for the iOS platform and how to implement it in your project.
  • Swift Best Practices and Tips by Toptal Developers (Publication)
    This resource contains a collection of Swift best practices and Swift tips provided by our Toptal network members.


  • Languages

    Swift, Swift 3, Swift 2, Objective-C, Java
  • Frameworks

    Cocoa Touch, UIkit, Core Data, AFNetworking, Cocos2d
  • Libraries/APIs

    Fabric, Core Animation
  • Tools

    Xcode, Git, Crashlytics, Trello, Jira, Confluence, Android Studio
  • Paradigms

    Object-oriented Programming (OOP), REST, Agile Software Development
  • Platforms

    iOS, Firebase, Android
  • Storage



  • Master's degree in Software Engineering and Information Systems
    2009 - 2011
    Faculty of Electrical Engineering and Computing, University of Zagreb - Zagreb, Croatia
  • Bachelor's degree in Computing
    2006 - 2009
    Faculty of Electrical Engineering and Computing, University of Zagreb - Zagreb, Croatia
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