Igor Delac, Developer in Split, Croatia
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Igor Delac

Verified Expert  in Engineering

Java Developer

Split, Croatia

Toptal member since November 3, 2014

Expertise
VoIPLDAPLinuxAsteriskJavaVaadinDevOpsGitHubREST APISpring BootMySQLApache KafkaAnsibleCisco
Bio

Igor is a highly skilled technology enthusiast with over 13 years of experience in Java development, system administration, and more. He loves to experiment and work with new technologies. Igor is very proud of his ability to learn whatever is necessary to solve a problem at hand.

Portfolio

SedamIT d.o.o.
Apache Maven, Eclipse, Event-driven Programming, Spring, Git, PostgreSQL...
Ericsson Nikola Tesla
Eclipse, UnboundID, Event-driven Programming, LDAP, Git, Java, Linux
Ericsson San Jose
GPON, UnboundID, Event-driven Programming, Git, SQL

Experience

  • Linux - 10 years
  • VoIP - 9 years
  • Java - 7 years
  • Spring LDAP - 4 years
  • SQL - 4 years
  • LDAP - 3 years
  • Vaadin - 3 years
  • Spring 5 - 2 years

Availability

Part-time

Preferred Environment

Eclipse, IntelliJ IDEA

The most amazing...

...project was a VoIP recording system for Cisco Call Manager, which was developed using a test-driven concept.

Work Experience

Java Developer

2017 - PRESENT
SedamIT d.o.o.
  • Developed a lawful interception system for monitoring telecom network traffic.
  • Created an RMS system for active VoIP call recording.
  • Migrated one major project from the Spring 3 to the Spring 5 framework.
Technologies: Apache Maven, Eclipse, Event-driven Programming, Spring, Git, PostgreSQL, Networking, Ansible, SIP, Asterisk, IP PBX, Interactive Voice Response (IVR)

Java Developer

2013 - 2015
Ericsson Nikola Tesla
  • Tested and developed test tools for a provisional gateway for the HLR system.
  • Created support for LDAP by implementing OpenLDAP and custom Java LDAP servers.
  • Built a high-performance LDAP server for testing (mobile) HLR systems.
  • Worked as a support engineer for some Linux tools.
  • Optimized the TCP stack on Linux 2.6 and 3.0 kernel series.
Technologies: Eclipse, UnboundID, Event-driven Programming, LDAP, Git, Java, Linux

Software Tester

2011 - 2012
Ericsson San Jose
  • Installed the Entrisphere/Ericsson BLM1500 multiplexer.
  • Tested BLM1500 data, video, and voice services for the Spirent Test Center.
  • Installed and supported Asterisk PBX for testing VoIP.
  • Configured extreme L3 Switches.
  • Troubleshot networks.
  • Tested GPON access to the network with ONT terminal provisioning.
Technologies: GPON, UnboundID, Event-driven Programming, Git, SQL

Integration and Verification Engineer

2008 - 2011
Ericsson Nikola Tesla
  • Conducted support for test tools.
  • Tested Linux-based elements of Telephony Softswitch Solution 4.0.
  • Troubleshot and diagnosed network problems.
  • Conducted SIP protocol analysis.
  • Integrated site system testing via installation and configuration of TGC/MGW elements.
Technologies: GPON, UnboundID, Git, Telephony

Network Administrator

2007 - 2007
Siemens PSE
  • Supported the introduction of multicast in the company network.
  • Created documentation for the network.
  • Diagrammed network connections.
  • Tested multicast on Cisco switches.
  • Tested multicast across routers.
  • Created final documentation and reported on test results.
Technologies: Multicast, Cisco

Experience

VoIP Call Recording System

A Java-based back-end system for VoIP call recording that used Spring for the back end and Vaadin for the UI.

It included:
• SIP, RTP protocols, compression using G.729 standard.
• OPUS encoder and decoder with OGG file container.

Designed an alarm subsystem and the web UI.

Simple Management System

A simple management front-end application coded in Java FX, to demonstrate REST approach and FX user interfaces. Back-end PHP and SQL scripts are also provided for integration into Apache web servers with a PHP module and MySQL database.

VNC Server Library for Java

https://github.com/idelac3/RFBService
A VNC allows remote connection and control of the host system, and it is used as an alternative to Microsoft RDP and TeamViewer. This project shows how to implement the server-side protocol in pure Java. The official name of the protocol is "Remote Frame Buffer," or RFB for short. This project compiles into a Java library as a JAR file and is also available as a Maven artifact.

Education

2002 - 2008

Master's Degree in Electrical and Software Engineering

J. J. Strossmayer University - Osijek

Certifications

APRIL 2012 - PRESENT

CCNA

Cisco

Skills

Libraries/APIs

Spring LDAP, libvirt, REST APIs

Tools

Apache Maven, Asterisk, Remote Framebuffer Protocol (RFB), Apache ZooKeeper, Eclipse IDE, OpenVPN, KVM/Qemu, Wix Installer, GitHub, Ansible, Git, FreeSWITCH, IntelliJ IDEA

Languages

Java, Bash, Assembler, SQL, Bash Script

Frameworks

Spring, Spring 5, Vaadin, Apache CXF, Thymeleaf, Spring Boot

Paradigms

Procedural Programming, Event-driven Programming, ASN.1, DevOps

Platforms

Linux, JavaFX, UnboundID, Apache Kafka, Eclipse, NetBeans

Storage

MySQL, PostgreSQL, Redis

Other

Cisco, Telephony, LDAP, VoIP, Session Initiation Protocol (SIP), RTP, Telegram Bots, SIP, Multicast, Networking, IP Routing, Dogtag PKI, Infrastructure, DevOps Engineer, CI/CD Pipelines, IP PBX, Interactive Voice Response (IVR), GPON, Cisco CallManager, PKI, WebSockets, FreeIPA, FreeRADIUS, Kerberos, Opus

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