Zoran Plesko, iOS Developer in Zagreb, Croatia
Zoran Plesko

iOS Developer in Zagreb, Croatia

Member since February 26, 2014
Zoran is a senior developer specializing in iOS, Java, and Ruby on Rails, and leads a development team at his company. After 15 years of developing core banking systems in Java for major banks and financial institutions and becoming an expert in card processing solutions, he decided to turn to the more fast-paced environment of web and mobile development. He regularly researches and learns new technologies and is an excellent problem solver.
Zoran is now available for hire




Zagreb, Croatia



Preferred Environment

Git, Sublime Text, Xcode

The most amazing...

...thing I've coded and designed is a module for card management software that interfaces MasterCard and Visa and is 95% maintained by a non-programmer.


  • Senior IT Specialist

    2013 - PRESENT
    Masinerija d. o. o.
    • Led development efforts, coordinating, delegating, and monitoring work among the team members when working on the same projects.
    • Created a Ruby on Rails back-end that supports a mobile social network based on JSON API, complete with in app purchase support and a push notification server running in the background without affecting the web server process.
    • Integrated image processing into an iOS application made for a festival for animated films so that users can make stop motion films and share them with their friends. Included an option for taking photos with the festival logo.
    • Served as a lecturer at various programming workshops (Android, iOS, and programming smartphones as musical instruments).
    • Developed a location-based application for delivering information about museums in Croatia and a similar app about restaurants and food products. Both apps are usable offline because their data is custom-synced to the online database.
    Technologies: Amazon Web Services (AWS), AWS, Heroku, Java, Ruby on Rails (RoR), Objective-C
  • Audio Engineering and Software Development

    2012 - 2013
    • Completed freelance development of several iOS apps.
    • Was responsible for composing and producing commissioned music for TV shows, animated movies, and commercials.
    • Recorded various bands and was responsible for mixing and postproduction.
    Technologies: Ruby on Rails (RoR), Objective-C
  • IT Architect

    2001 - 2012
    Vestigo d. o. o.
    • Designed and developed parts of a proprietary framework for rapid development of business software (a parametric menu system in Swing backed by DB2 and synced with a server).
    • Designed and developed an interface layer between Vestigo's card management software and MasterCard, Visa, and Diners financial services. Was responsible for implementing Visa, MasterCard, and Diners data formats, interfacing them to the database and making the parser and generator configurable to make changes in the data format parameterizable by a non-programmer business analyst.
    • Coordinated the client's and Vestigo's in-house team two times a year on a three-month project to implement changes introduced in MasterCard, Visa, and Diners financial services.
    • Mentored and educated new programmers. Used in-depth knowledge of the proprietary framework to add unsupported features (uploading files to information systems from Citrix terminals). Developed a lot of features in Vestigo's business software package. Provided business requirement analysis in card management and worked with clients from Italy and Slovenia on the analysis of their business processes.
    • Reworked an especially complex part of a collection module of Card Management Software from code that introduced many different errors in data to atomized code that had clear logical units of work and worked according to expectations.
    Technologies: IBM Db2, CICS, AIX, z/OS, Java EE
  • Back-end/Front-end Developer

    2000 - 2001
    Iskon d. o. o.
    • Developed a multiplayer games as Java plugins for a proprietary chat engine on Iskon's web portal. The chat engine was written as a Java Applet and had an interface that enabled us to create Java applets which could communicate with each other. I worked on a 4 in a row game and chess (no AI, just multiplayer).
    • Developed parts of a CMS in JSP and related technologies. Developed the engine for serving campaigns.
    • Developed a classifieds website based on Oracle, Tomcat, Apache, and JSP.
    • Ported ASP code to JSP for a part of the "Klik" portal. Acquired by Iskon.
    Technologies: Apache Tomcat, Apache, JSP, Java Application Servers


  • Huxly News

    I worked on developing a platform for delivering curated news, sourcing users' opinions and visualizing them on a highly interactive map.

    The back end was developed in RoR and Grape on Rails, deployed to AWS, dockerized and set up on ECS Fargate, ready to scale.

    The client got an offer to sell the app to another enterprise and is currently working out a deal. We pulled the app from the App Store because we developed a pivoted version where we dropped the news delivery part and emphasized the crowdsourcing of opinions, which is about to be released on the App Store as soon as the client is ready.

  • Living Scriptures International

    A Netflix-like website with iOS, Android, and Roku apps.

    I was in charge of making the transition from Wowza server to being able to serve HLS transcoded adaptive bitrate videos through AWS Cloudfront for a much cheaper price and for implementation of JW Player on the website.

    I also worked on various other parts of the Rails app (PayPal integration, payment gateway integration) and saved a badly-made outsourced iOS app from being thrown away by rewriting 80% of it to comply with best practices in app making, ultimately speeding it up by more than 10 times. I wrote the video player portion to mimic Netflix by functionality.

  • Collide

    A system for video streaming and chatting with celebrities through mobile apps and web. I was part of the iOS team, in charge of keeping the UI in place, rewriting it from a previous version that did not satisfy Apple's human interface guidelines.

  • Whatt

    Whatt is a fresh and simple way to share status updates among friends. It's an iOS-only social network and messaging app.

  • Create To Heal™ iOS

    An app that accompanies the Create To Heal™ program for stress relief and self healing. The app is private, meaning that the user has to request a PIN number (served through the Ruby on Rails back-end) to be able to use the app. Once in, the user has access to guided meditations, music, and an art slide show through a custom-made multimedia player.

  • Create To Heal™ Android

    The Android version of the Create To Heal™ program app.

  • Taste of Croatia

    An independent guide to good food, wine, local produce, eateries, and foodie events in Croatia. My first iOS project. It got me interested in iOS and mobile development.

  • Cro Museums

    Croatian Museum info all in one place. This was my first project using Ruby on Rails. After that, I fell deeply in love with Ruby on Rails, making it my number one choice for back-end solutions.

  • Animafest

    A catalog and schedule planner for a world-famous festival of animated films. Beside the program part, the client wanted something fun, so I made two "games." Festival mascot Mandlek joins you when taking pictures from the app, and users can make their own stop motion films and share them to Facebook.

  • Make-up Tutorials by Simona Antonovic

    Series of very simple applications for iOS and Android used for the client's promotional purposes.

  • Vrtii

    Vrtii is an innovative way of advertising - users play a game via a mobile application and win prizes that they can redeem at the advertiser's store or trade with other users via a mobile application exchange market.

    My team and I developed the whole system from scratch, using Ruby on Rails for back-end for both web and iOS applications. I developed the game within the mobile application using SpriteKit.

    The web application is aimed at advertisers and allows them to register and create campaigns and the mobile application is aimed at users who can play a game and win prizes set by advertisers. I created an algorithm for distribution of the games that are available to be won. Displaying/winning a prize depends on targeting set by advertiser, and we also made it location sensitive.

    At the moment, the client is waiting for the Android application to be finished and is preparing to launch the project.


  • Languages

    Swift, Objective-C, SQL, Ruby, Java, JavaScript, HTML
  • Frameworks

    Core Data, Ruby on Rails (RoR), GrapesJS
  • Tools

    Xcode, Git, AWS Fargate, Amazon ECS (Amazon Elastic Container Service), Docker Compose
  • Paradigms

    Model View Controller (MVC), Object-oriented Programming (OOP), Concurrent Programming, REST, Object-oriented Design (OOD), Model View Viewmodel (MVVM), Dependency Injection
  • Platforms

    iOS, Heroku, tvOS, Amazon Web Services (AWS), Amazon EC2 (Amazon Elastic Compute Cloud), Oracle, Android, Docker
  • Storage

    SQLite, Amazon S3 (AWS S3), PostgreSQL, IBM Db2, MySQL
  • Libraries/APIs

    SpriteKit, Twitter SDK, REST APIs, Facebook iOS SDK, Redis Queue, Resque, RxSwift
  • Other

    iOS Animations, Amazon Elastic Transcoder, SOAP, AWS


  • Master's in Science Degree in Telecommunications and Computer Science
    1995 - 2001
    Faculty of Electrical Engineering and Compute Science - Zagreb, Croatia


  • AWS Solutions Architect Associate
    JULY 2020 - JULY 2023
    Amazon Web Services Training and Certification

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