Josip Blažević, Developer in Zagreb, Croatia
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Josip Blažević

Verified Expert  in Engineering

Java Developer

Zagreb, Croatia
Toptal Member Since
May 16, 2017

For over the past 17 years, Josip has worked as a software engineer developing and integrating mission-critical enterprise applications and systems. He specializes in current front-end and Java-based back-end technologies and is extremely adept at finding the most-simple-but-effective solutions for complex engineering problems. Through his many leadership roles, he has developed strong communication skills and a proactive, can-do mentality.


Celarent Ltd.
Liferay, Swagger, REST, JAX-RS, OSGi, Vue, CSS3, HTML5, JavaScript, JEE, Java
S&T Hrvatska d.o.o
Oracle Database, Data Warehouse Design, Data Warehousing, IBM Filenet...
S&T Hrvatska d.o.o
Node.js, Scala, Java, Informatica PowerExchange, Oracle Database...




Preferred Environment

IntelliJ IDEA, Git, Vim Text Editor, Eclipse, Linux, MacOS

The most amazing...

...code I've implemented is an IEEE spec-compliant compiler for the VHDL hardware description language.

Work Experience

Software Engineering Architecture Consultant

2017 - PRESENT
Celarent Ltd.
  • Worked as a self-employed software engineering and architecture consultant.
  • Developed a public-facing customer self care portal for a major telecom provider.
  • Established the development framework and incorporated the needed technologies and libraries.
  • Sliced the CSS, HTML, and SVG assets from the supplied UX designs.
  • Developed an OpenID Connect integration module for SSO.
Technologies: Liferay, Swagger, REST, JAX-RS, OSGi, Vue, CSS3, HTML5, JavaScript, JEE, Java

Applications Manager

2013 - 2016
S&T Hrvatska d.o.o
  • Led a 15-person team focused on enterprise application and solution development.
  • Worked on a variety of projects, including custom application development, data warehousing/BI, and the development of document management solutions.
  • Managed people, finances, pre-sales, contract negotiations, and project delivery.
  • Maintained my own technical skills and performed development work when needed.
  • Developed a public-facing case law portal for the Supreme Court of the Republic of Croatia and integrated it with the European Commission's European e-Justice Portal.
Technologies: Oracle Database, Data Warehouse Design, Data Warehousing, IBM Filenet, Apache Tomcat, Apache, Solr, JEE, Java

Principal Consultant | Project Manager

2011 - 2013
S&T Hrvatska d.o.o
  • Managed the vendor side of a complete data warehouse redesign project for a major telecom. Led a 10-person team, with a total of ~40 people participating on both sides.
  • Established a sound requirement management discipline and a predictable development process. Insisted on an open, transparent process and sincere communication.
  • Established quality criteria and drove the development of test automation.
  • Developed tools that helped made the project team more efficient, including specialized reporting and coordination tools for the project tracking system, using Scala and Node.js.
  • Completed the project successfully, resulting in strong client satisfaction and ongoing work for the company.
Technologies: Node.js, Scala, Java, Informatica PowerExchange, Oracle Database, Data Warehouse Design, Data Warehousing

Chief Software Engineer

2006 - 2011
  • Acted as the team leader/architect role on various custom software development projects for the banking and telecom industry.
  • Led the development of two custom CRM solutions for the largest Croatian bank based on the IBM WebSphere Portal.
  • Integrated enterprise systems with technologies like z/OS CICS, IBM MQ, IBM Message Broker, Web Services, and more.
  • Led the development of a public website for a telecom company based on Liferay Portal.
  • Influenced technology choices and software architecture across the department projects.
Technologies: WebSphere, Portlets, IBM Db2, Web Services, JAX-WS, Hibernate, Spring MVC, Spring, JEE, Java

Software Engineer

2003 - 2006
Combis Ltd.
  • Acted in the software developer role on various projects for the banking industry.
  • Developed a Java/Swing based client-server debt collection system.
  • Developed an outbound call management integration, agent conversation script functionality, and a web chat for an IP call center system.
  • Invented AJAX-style iframe-based dynamic communication for the web chat app in 2004, a year before the AJAX term was coined.
  • Acted in the capacity of the first team lead/project manager role for a debt collection system for a new customer (after working there for 2 years). The project was named the best of 2005 for the customer.
Technologies: Cisco, IBM Db2, Hibernate, Apache Struts, Enterprise Java Beans (EJB), Servlet, Swing, Java

Sample Booking Application

A sample booking application is a simple business app built entirely with standard Java APIs and no other dependencies. It includes a client, server, and a simple database engine. The client is a Swing-based desktop app. The client-server communication is based on RMI. The database engine supports record CRUD and locking operations to allow for multi-user operations.

Portal of Case Law for the Supreme Court of the Republic of Croatia
This is a custom portal based on Java Servlets, Struts, HTML5, and jQuery and backed by the Solr search engine. It's a high performance law document search with custom stemming for the Croatian language. It's also integrated with the European Commission's European e-Justice Portal for which it provides a source of Croatian case law decisions. Its social impact is that it has democratized and sped up access to Croatian case law material and made it easy to be consumed by lawyers, judges, law students, and the general public. Its political impact was that it furthered Croatia's European integrations.
1998 - 2003

Master's Degree in Computer Engineering

University of Zagreb, Faculty of Electrical Engineering and Computing - Zagreb, Croatia


Vue, JAXB, JAX-WS, JMS, JSR 286, JSR 168, JDBC, JSTL, React, JAX-RS, jQuery, jQuery UI, Node.js


Servlet, Eclipse IDE, IBM Rational, JBoss Drools, Apache Maven, Apache Tomcat, Redmine, Vim Text Editor, Apache Ant, Java Concurrency, Apache HTTP Server, Apache Solr, Solr, Apache, IBM Filenet, Informatica PowerExchange, IntelliJ IDEA, Microsoft Visual Studio, Git, Jira, Mercurial, Apache JMeter, Subversion (SVN), GCC, Webpack 2


JPA, Rational Unified Process (RUP), Spring MVC, Jakarta Server Pages (JSP), Hibernate, Spring, Apache Struts 2, Mockito, Swing, JUnit, OSGi, Swagger, Apache Struts, Arquillian


SQL, Java, JavaScript, UML, CSS3, HTML5, C, ECMAScript (ES6), Haskell, BPEL, Scala, C++, Rust


Object-oriented Design (OOD), Object-oriented Programming (OOP), Requirements Analysis, BPMN, REST, Test-driven Development (TDD), Functional Programming, Responsive, Scrum, CRUD


IBM WebSphere, JEE, Linux, MacOS, Eclipse, WebSphere, Oracle Database, WebSphere MQ

Industry Expertise

Project Management


Elasticsearch, PostgreSQL, IBM Db2, JSON/XML Schemas


Portlets, Software Architecture, Data Modeling, Enterprise Software, Enterprise Integration, Debugging, Troubleshooting, EJB 3, Embedded Software, Apache Commons, Enterprise Integration Patterns (EIP), Liferay, HTTPS, HTTP, Project Planning, Hamcrest, SOAP, Enterprise Architecture, Data Warehousing, Web Services, Cisco, Data Warehouse Design, g++, Network Programming, Ubuntu Server, Enterprise Java Beans (EJB), APIs

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