Mladen Josipović, Software Developer in Zagreb, Croatia
Mladen Josipović

Software Developer in Zagreb, Croatia

Member since November 18, 2013
Mladen is a senior Java developer, application and system designer, and architect. By working as the system integrator in a large telecom environment, he has extensive experience in using a wide range of programming languages, technologies, and tools on different platforms.
Mladen is now available for hire


  • Druga Derivacija d.o.o.
    IBM WebSphere, Apache Tomcat, PL/SQL, JavaScript, Hibernate, Spring...
  • Belk
    React Native, Redux, Redux-Saga, Redux Toolkit,, Flybuy, TypeScript
  • VineLight (via Toptal)
    Amazon Web Services (AWS), Security, JPA, Spring Boot, Java Amazon SDK...



Zagreb, Croatia



Preferred Environment

Linux, Windows, MacOS, Visual Studio Code, VS Code

The most amazing...

...thing I have coded is a complete interactive program for analysis, recognition, and vectorization of curves which is used in cartography.


  • Owner, Senior Consultant, System Integrator

    2012 - PRESENT
    Druga Derivacija d.o.o.
    • Developed a React Native application used as part of an IoT platform.
    • Created and maintained a native Android application used as part of an IoT platform.
    • Designed and developed a native Android application for a gas utility company. Field workers use the application to collect gas consumption data.
    • ­Developed native Android application that is used as the museum’s catalog. The application runs on an Android tablet with NFC functionality, multimedia features, exhibits positioning on the museum floor sketch, and multi-language support.
    • Developed a Java back-end module for a startup solution related to internet security.
    • Developed an application using Java, SOAP, and Oracle that synchronizes data between ERP and commercial systems in a large gas distribution company.
    • Developed the commercial system for a large gas distribution company, working as the application architect, senior developer, and team leader.
    • Implemented statistical regression methods in PL/SQL used to forecast gas consumption.
    • Worked on a PoC for an image capturing and video streaming project implemented on the Raspberry Pi on the client-side and Java web app. on the server-side. Technologies used: Raspberry Pi, GPIO, Python, Java, Spring Boot/JPA/Security, REST, AWS.
    • Designed and developed a back-end module that provides a REST interface over the part of the ERP database for a gas utility company.
    Technologies: IBM WebSphere, Apache Tomcat, PL/SQL, JavaScript, Hibernate, Spring, Android SDK, Java, React Native
  • React Native Engineer

    2021 - 2021
    • Developed new mobile application features related to deep linking, Branch SDK integration, Flybuy SDK integration.
    • Worked with Redux Toolkit, React navigation, and TypeScript.
    • Contributed to fixing bugs and used Jira as a tracking issues tool.
    Technologies: React Native, Redux, Redux-Saga, Redux Toolkit,, Flybuy, TypeScript
  • Expert Java Developer

    2015 - 2016
    VineLight (via Toptal)
    • Created a data model in Dynamo DB.
    • Used AWS Java SDK to work with AWS's Dynamo DB, IAM, and SES.
    • Used Java and Spring framework to create a REST API around data stored in Dynamo DB.
    • Configured and implemented security based on Spring security and OAuth2.
    • Deployed a Java web application on AWS Elastic Beanstalk.
    Technologies: Amazon Web Services (AWS), Security, JPA, Spring Boot, Java Amazon SDK, AWS SDK, Amazon DynamoDB, AWS Elastic Beanstalk, OAuth 2, REST, Java
  • Android Developer

    2015 - 2015
    Audio Global, LLC (via Toptal)
    • Redesigned a complete UI and developed new features for this Android MP3 player application using NDK special native library, providing different tuning effects.
    • Implemented in-app billing to provide a subscription model for the application.
    • Published the application to the Google Play store.
    • Ensured that the application was created to support a wide range of Android devices.
    Technologies: Android NDK, Android SDK, Java
  • Senior Android Developer

    2015 - 2015
    Teracode (via Toptal)
    • Developed an Android application for remote controlling a robot.
    • Developed user interface elements according to strict requirement specifications and Android best practices.
    • Communicated with the back end via RESTful web services.
    • Implemented business logic.
    • Handled Agile project management with advanced usage of GitHub.
    Technologies: GitHub, Rally, Spring, Android
  • Developer

    2014 - 2015
    Templeton Mortgage (via Toptal)
    • Fixed bugs in a custom application developed on the MS SQL platform with UI developed in MS Access.
    • Added new features to the custom application developed on the MS SQL platform with UI in MS Access.
    • Integrated with Google and Bing mapping services.
    • Developed SQL procedures for automation of the business process.
    • Optimized SQL queries.
    Technologies: Visual Basic for Applications (VBA), Microsoft Access, Microsoft SQL Server
  • UI Developer

    2014 - 2015
    Iddy (via Toptal)
    • Created an Android application for a gate entry proof-of-concept project.
    • Integrated the application with access control and an identification system in the back end.
    • Displayed patron information in a fragment-based application running on the Android tablet.
    Technologies: PHP, Oracle, Apache HttpClient, Java, Android
  • Developer

    2014 - 2014
    John Plunkett (via Toptal)
    • Created a pilot mail delivery service based on the Mailgun API service. Developed the system in Java. Used Mailgun REST API, Jersey, MySQL database, and H2 embedded database.
    Technologies: GSON, Jersey, Mailgun, H2, MySQL, Java
  • Senior Consultant, System Integrator, Application Developer

    2008 - 2012
    Recro-net d.o.o. Zagreb
    • Developed a testing platform for the middleware for an IPTV project for a large telecom and broadband provider.
    • Developed the company's parking management system.
    • Integrated and administered the Compuware Agentless system that measures EUE for enterprise users.
    • Integrated and administered the Compuware VSC system for per-subscriber DSL troubleshooting and service delivery monitoring.
    • Designed and implemented the business service management system for a large telecom provider using Compuware VSM system, JavaScript, Rhino, and Shell script.
    • Developed multiple utility programs for integration of the Nagravision system (Direct-To-Home platform) with OSS/BSS systems.
    • Developed the pilot application for integration with a Subscriber Management System gateway using C-based API for messaging purposes.
    • Developed widgets for Nagravision Direct-To-Home platform using JavaScript, PHP, and HTML.
    Technologies: Python, Shell Scripting, JavaScript, C#, C++, C, Java
  • System Integrator, Application and System Developer, Support Engineer

    2002 - 2008
    Fornax Informatika d.o.o.
    • Integrated and maintained the fault management system and network management system for a large telco provider using IBM Tivoli Netcool/OMNIbus, Netcool/Impact, Netcool/Reporter, Netcool/Webtop, and Network Node Manager.
    • Oversaw the system integration project for a mobile provider using Java, LDAP, and IBM Tivoli Netcool.
    • Supervised the system integration project for a telco provider, integrating their trouble ticketing system and fault management system.
    • Developed many utility programs and scripts on Unix systems for automation and integration purposes.
    • Integrated the reporting system system based on Crystal Reports with a web application for presentation.
    Technologies: JavaScript, HTML, Perl, Unix Shell Scripting, Java
  • Application Designer, System Designer, and Developer

    2000 - 2002
    OKIT d.o.o. Zagreb
    • Designed, developed, and implemented the database application for the trouble call system for Distribution Utility using MS Visual C++, Visual Basic, Oracle, ODBC, and Crystal Reports.
    • Developed back-end PL/SQL procedures to support fault management system and to automate tasks.
    • Developed a small commercial application specifically designed for companies dealing with DTP business using MS Visual Basic, MS Access, ADO, and Crystal Reports.
    • Integrated the reporting system with a commercial application.
    Technologies: Crystal Reports, Visual Basic, C++, C
  • System and Database Administrator, Application Developer

    1998 - 2000
    FED d.o.o. Zagreb
    • Provided system administration for the large marketing agency using MAC OS and Windows.
    • Maintained the database using ACI 4th dimension and Oracle.
    • Integrated data from commercial database with DTP programs (QuarkXPress) with purpose to automate newspaper page creation.
    • Developed multiple small database applications in MS Access.
    Technologies: Oracle, Microsoft Access, 4D, C
  • Application and Database Designer and Developer

    1994 - 1998
    Fotosoft d.o.o. Zagreb
    • Created many utility applications in C, which are used in cartography: Geometrical transformations (2D) applied on computer images, color analysis and separation applied on color images, and different filters based on geometrical recognition with given parameters.
    • Developed the complete interactive program for analysis, recognition, and vectorization of curves used in cartography.
    • Designed, programmed, and implemented a database application for a large marketing agency using 4 dimensions.
    • Developed an application which transforms bitmap images to security vector graphic images using C.
    • Created different filters based on geometrical recognition with given parameters using C and Adobe Photoshop.
    Technologies: Clipper, 4D, C


  • Enterprise Commercial System for a Gas Distribution Company

    Designed and developed the Java EE based enterprise system for a large gas company. The system runs on the IBM Websphere platform with internal and external system parts. Multi-tier application architecture with Oracle database in the back-end, Hibernate in DAO layer and Spring framework as a container. The web layer is realized with Dojo framework on an internal system and ICEfaces on the external. Complex business rules and user requirements, yet short time to develop the application. All requirements satisfied completely and on time.

  • Special Audio Player for Android

    Developed the main GUI component for a special audio player for Android. The application was developed as a native Android application using specific libraries written in C for tuning effects.

  • Intel Hex Files to Proprietary Encrypted Format

    Developed a program to process Intel hex files and transform them to a proprietary encrypted format. The program was written in C/C# and built for the Microsoft Windows platform.

  • Android Software for Hardware-customized Phones

    Developed an application used on specially hardware customized Android phones with external cameras to take photos and videos and upload automatically to a server or send by email.

  • Digital Image Rendering Analysis Project

    Helped develop special Java software for digital map rendering analysis with two particular functions: Image comparison and pattern matching.

    Tech stack: Java, PostgreSQL, PTV xMap server, Hibernate, Servlet, Maven, JUnit.

  • Android Application for Museum Catalog

    Native Android application that is used as the museum’s catalog. The application runs on an Android tablet with NFC functionality integrated, multimedia features, exhibits positioning on the museum floor sketch, and multi-language support.

  • Back-end Module in Java

    Designed and developed a module which provides a REST interface over the part of ERP database.

    Tech stack: Java, Spring Boot/JPA/Security, REST, Oracle.

  • Native Android Application for a Gas Utility Company

    Designed and developed an application used by field workers to collect gas consumption data and to synchronize collected data with the central database.

    Tech stack: Native Android, NFC, SQLite, Retrofit.

  • Mobile Application for IoT Platform

    Developed a React Native application which is used as part of the IoT platform.

    Tech stack: React Native, Redux, Android, iOS, Firebase, React Native Charts Wrapper.

  • Java Back-end Module

    Developed a back-end module used as the part of the solution related to internet security.

    Tech stack: Java, Spring, MySQL, RabbitMQ, REST, OAuth2.


  • Languages

    Java, SQL, JavaScript, UML, Bash Script, C++, C, Visual Basic, HTML, Clipper, PHP, Visual Basic for Applications (VBA), Python, Perl, C#, TypeScript
  • Frameworks

    Spring Security, Hibernate, React Native, Spring, JavaServer Pages (JSP), Android SDK, Jersey, OAuth 2, Spring Boot, JPA, JavaServer Faces, Dojo, Redux
  • Tools

    Eclipse IDE, RabbitMQ, Maven, Crystal Reports, IBM Rational, Keycloak, Apache Tomcat, Microsoft Access, Rally, GitHub, Android NDK, AWS SDK, Java Amazon SDK, Cacti, LaTeX, VS Code,
  • Paradigms

    Object-oriented Programming (OOP), Microservices, REST, Layer Programming, Dependency Injection, Procedural Programming, Model View Controller (MVC), Unit Testing, Design Patterns, Event-driven Programming, Concurrent Programming, Continuous Integration (CI), Continuous Delivery (CD)
  • Platforms

    JSE, NetBeans, Android, Linux, Unix, Windows, Java EE, Oracle, IBM WebSphere, Mailgun, Eclipse, AWS Elastic Beanstalk, Amazon Web Services (AWS), Docker, Raspberry Pi, MacOS, Firefox, Visual Studio Code
  • Libraries/APIs

    React Redux, JasperReports, Java Servlets, Node.js, GSON, Apache HttpClient, iText, Twilio API, Redux-Saga
  • Storage

    MySQL, Database Modeling, Oracle PL/SQL, PL/SQL, H2, Amazon DynamoDB, PostgreSQL, Microsoft SQL Server
  • Other

    SOAP, Unix Shell Scripting, Mathematics, Shell Scripting, 4D, Informatics, Near-field Communication (NFC), Network Programming, Ajax, Single-page Applications (SPA), Animation, Push Notifications, Software Architecture, Redux Toolkit, Flybuy, APIs
  • Industry Expertise



  • B.Sc. Degree in Applied Mathematics and Informatics
    1988 - 1994
    University of Zagreb - Zagreb, Croatia


  • React Native - The Practical Guide [2022]
    MAY 2022 - PRESENT
  • Master CI/CD for React Native
    APRIL 2022 - PRESENT
  • React Native: Advanced Concepts
    APRIL 2022 - PRESENT
  • Software Architecture Case Studies
    MARCH 2022 - PRESENT

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