Danijel Gornjaković, Developer in Belgrade, Serbia
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Danijel Gornjaković

Verified Expert  in Engineering

Full-stack Java Developer Developer

Location
Belgrade, Serbia
Toptal Member Since
June 29, 2020

Danijel is an accomplished full-stack Java developer with more than a decade of professional experience. He is well-versed in both back-end and front-end work, databases (SQL and NoSQL), and DevOps. Danijel puts clients' needs first and makes sure they get optimal value from software.

Apache CassandraJavaSQLNoSQLNeo4jJiraSpringMongoDBPSM-1CSSJenkinsDevOpsBambooXMPPWindowsFreeMarkerRaphaëlLiferayAlfresco

Portfolio

Markant
Cassandra, Neo4j, MongoDB, Angular, Spring Data, Spring, Java
Adama Regstore
YUI, Alfresco, Java
Adama Public Website
JSON, FreeMarker, jQuery, Liferay, Java

Experience

Java - 12 yearsJavaScript - 10 yearsSpring - 6 yearsNeo4j - 5 yearsDevOps - 5 yearsApache Cassandra - 3 yearsMongoDB - 3 yearsAngular - 3 years

Availability

Part-time

Preferred Environment

Java, Eclipse, IntelliJ IDEA, Linux, Windows

The most amazing...

...software I've worked on was a big data project combining three NoSQL databases—MongoDB, Neo4j, and Apache Cassandra—to deliver fast read and write throughput.

Work Experience

Lead Developer

2018 - 2020
Markant
  • Developed a validation module built with MongoDB and Kafka messaging with Angular to visualize the data.
  • Designed and developed a forecast data module with the Apache Cassandra database.
  • Configured and maintained Jenkins and GitLab CI/CD pipelines for various docker and GitFlow jobs.
  • Developed a master data model and import logic using Spring Data and Neo4j.
Technologies: Cassandra, Neo4j, MongoDB, Angular, Spring Data, Spring, Java

Lead Architect

2017 - 2018
Adama Regstore
  • Led a team of four developers as both the scrum master and lead architect. I solicited requirements from the client and made sure the team delivered them as intended.
  • Established the architecture of the project; handled DevOps tasks to configure CI/CD using Bamboo; and set up the development, QA, and production environments.
  • Implemented and oversaw the release process, which required an initial import of more than 100,000 documents with the client's metadata.
  • Developed an OCR module using Adobe Backend Services API and Apache Solr search implementation.
Technologies: YUI, Alfresco, Java

Senior Full-stack Developer

2016 - 2017
Adama Public Website
  • Developed the migration module that would transfer all content from an SQL database to a JSON format compatible with Liferay and then oversaw the import.
  • Participated in the initial setup and configuration of the Liferay environment.
  • Developed several portlets in Liferay with Spring MVC and jQuery.
Technologies: JSON, FreeMarker, jQuery, Liferay, Java

Senior Full-stack Developer

2015 - 2016
Adama Knowledge Hub
  • Co-developed the data model for a Neo4j database to represent a real-world use case for agricultural farmers in relation to crops and pesticides.
  • Handled back-end tasks to integrate Neo4j and Spring MVC into Liferay Portal.
  • Wrote and optimized Spring Data queries to meet the non-functional requirements of thousands of users needing runtime search results.
Technologies: Liferay, Neo4j, Spring, Java

Full-stack Developer, Scrum Master

2014 - 2015
Bosch
  • Co-developed a portlet that communicates with an IoT device to control smart home ACs. The device used XMPP protocol for communication.
  • Developed the UI of the portlet that would mimic the UI of the remote device to control the AC. We built the SVG UI using Raphael.js library.
  • Acted as the scrum master, ensuring that teams adhered to the Scrum framework.
Technologies: Raphaël, XMPP, Liferay, Java

Full-stack Developer

2013 - 2014
PRODYNA
  • Built and maintained a module integrating IBM Notes mail client into Liferay. The data was fetched using CORBA remote procedures.
  • Developed the logic to write emails using RichText editor and forward those emails from Liferay to a Lotus Notes server.
  • Analyzed the API possibilities of the IBM Domino database and designed the concept for how that data could be mapped to the common model we used.
Technologies: IBM Domino, Java EE, Liferay

Full-stack Developer

2010 - 2013
Heliant (Health Information System)
  • Developed a standalone business intelligence module for managing the inventory of medicines and other medical equipment.
  • Implemented ad hoc reporting using prepared queries and a custom-built UI.
  • Participated in release management and deployment of a new version to more than 50 servers.
Technologies: CSS, HTML, Jakarta Server Pages (JSP), JavaScript, MySQL, Hibernate, Java

Big Data Project with MongoDB, Neo4j, and Cassandra

I participated in a big data project with terabytes of data being imported and exported on a daily base. The project required a fast read and write throughput, so we had to model the data to different NoSQL databases and decouple and parallelize the import and export process. Communication between microservices was done using Feign clients and Kafka. The GUI for managing the workflows and querying the data was built using Angular and Angular Material.

Adama Public Website

https://adama.com/
I co-developed a public Liferay and Java-based portal. Each country had its own site (50 in total) with shared content types and a common look and feel. I built the migration module taking the data from the older SQL database and mapping it to a JSON module compatible with Liferay. I also built various portlets based on design and functionality requirements. And, finally, I worked on the LDAP and ADFS integration to build a single sign-on experience for the web editors.
2010 - 2011

Master's Degree in Computer Science

University of Belgrade School of Electrical Engineering - Belgrade, Serbia

2006 - 2010

Bachelor's Degree in Computer Science

University of Belgrade School of Electrical Engineering - Belgrade, Serbia

JANUARY 2016 - PRESENT

Certified Liferay Portal Developer

Liferay, Inc

JANUARY 2016 - PRESENT

Professional Scrum Master, Level 1 (PSM-1)

Scrum.org

JANUARY 2016 - PRESENT

Neo4j Certified Professional

Neo4j

JANUARY 2015 - PRESENT

Certified Professional for Requirements Engineering

International Requirements Engineering Board (IREB)

JANUARY 2013 - PRESENT

Java Certified Developer

Oracle

Libraries/APIs

YUI, jQuery, Raphaël

Tools

Jira, Jenkins, Bamboo, IntelliJ IDEA, Alfresco, FreeMarker

Storage

Neo4j, Spring Data, NoSQL, MongoDB, MySQL, Cassandra, JSON

Frameworks

Spring, Angular, Hibernate, Jakarta Server Pages (JSP)

Languages

Java, SQL, JavaScript, HTML, CSS

Platforms

Windows, Linux, Eclipse, Java EE, IBM Domino

Paradigms

DevOps

Other

Apache Cassandra, PSM-1, Liferay, XMPP

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