02/20/2026 updated

**** ******** ****
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Senior Java Developer

Biatorbágy, Hungary
Worldwide
M.Sc. Logistics
Biatorbágy, Hungary
Worldwide
M.Sc. Logistics

Profile attachments

Profil_Karoly_Gacsal_20251117.docx
Profil_Karoly_Gacsal_20251117.pdf
certificate_ethical_hacking.pdf

Java (Programming Language)JavaScriptApache TomcatServer ApplicationAutomationEclipse (Software)Enterprise JavaBeansJava Platform Enterprise Edition (J2EE)Google Web ToolkitsHibernateMobile Application SoftwareJavaFXJava Message Service (JMS)Java Persistence APIJava ServletWildFly (JBoss AS)Javaserver PagesJUnitApache MavenObject-Relational MappingAnsibleSeleniumSQL DatabasesVaadinWeb ApplicationsWeb ServicesTestingSpring BootVue.jsBackendContainerizationAngularJSFront End Software DevelopmentGoogle PlayDockerJenkins
I'm an experienced software developer with almost 25 years experience, mainly in the world of Java.
Developed many frontend and backend applications.

On the frontend side developed using different technologies:
- Web Applications
  - Angular
  - VUE.js
  - GWT/GXT
  - Vaadin
  - Javascript
- Eclipse RCP applications
- Java FX applications

On the backend side used technologies like:  
SQL, ORM, Hibernate, JPA, JEE (EJB, JMS) WebServices, Spring, div. application servers (Tomcat, JBoss), Spring Boot etc.

In the past years I got lot of experience in containerization (Docker Swarm) and also automated configuration deployment techniques, like Ansible.

I am experienced in continous integration and deployment, using tools like
Apache Maven, Jenkins, Testing-Frameworks (JUnit, Selenium), Docker.

In the last years developed mobile applications based on own ideas and brought the apps to the stores (AppStore, Google Play) and also implemented all the automation tasks necessary to drive a medical instrument.

I am happy if I can be a member of an Agile Team, but I am also able to work alone.
In the last 20 years I worked together remotely with an austrian customer, so I think borders between me and the customer are not a problem.

Experience

Professional experience10+ years
Freelancer since2002

Languages

GermanFluentEnglishFluent

Project history

Senior Backend Developer

Twinformatics GmbH.

Banking & Financial Services

250-500 team member

In diesem Projekt wurde eine neue Bankanbindung von einer Versicherungsanstalt erstellt. Dabei sollte ein
Processing-API erstellt werden, welche das Ausführen von Tasks in verschiedenen Schnittstellenservices
ermöglicht. Es wurden gleich zwei Schnittstellenservices mitimplementiert, die Clients von diesen Processing-API sind. Die Entwicklung erfolgte in einem kleinen Team von 3 Entwicklern.
Aufgaben- und Verantwortungsbereiche:
  1. Aufsetzen von Entwicklungs-, Test- und Betriebs-Umgebungen
  2. Erstellen von GitLab Projekten
  3. Erstellen von CI/CD Konfigurationen anhand existierenden Templates für
  4. Containers in GCP
  5. Google-Cloud Configs
  6. Anlegen von Grafana-Boards für Monitoring
  7. Backend
  8. Erstellung des Processing-APIs, welche Tasks und Subtasks managen kann
  9. Erstellung von Schnittstellenservices die das Processing-API nutzen
  10. Erstellung von spezifischen Metriken für Monitoring
Technologien, Werkzeuge:
Java, SpringBoot, Spring Batch, Schedlock, OpenAPI, Swagger, PostgreSQL, JOOQ, FlyWay, Prometheus,
Grafana, GCP, Kubernetes, JIRA, Confluence

AI-Automation Consultant

Healthware Kft.

Pharmaceuticals & Medical Technology

10-50 team member

For this customer, we created/modernized a framework system for the presentation
of medical evaluations in an earlier project (see below). The customer has huge amounts of data from
anonymized patient data with diseases/examinations/treatments.
In this project, we were given the task of providing a chatbot that takes the data
from a locally managed knowledge graph.

Tasks and responsibilities:
  • Backend
    • Creation of new endpoints for the chatbot
    • Calling N8N WebHooks
  • Frontend
    • Implementation of chatbot frontend
  • N8N
    • Creation of multiple workflows and AI agents
  • DevOps
    • Enabling on-premise operation of N8N containers in Docker Swarm of the customer
Technologies, tools:
N8N, Java, SpringBoot, Angular, Docker Swarm, Traefik, Portainer, JIRA, Confluence

Fullstack Developer

Twinformatics GmbH.

Banking & Financial Services

250-500 team member

In this project, the bank connection had to be created for an insurance company.
New frontend components were developed and new API endpoints were offered at the backend. 
The development was carried out remotely in a 10-person Scrum team.

Tasks and areas of responsibility
  • Backend
    • Creation of new endpoints for the interfaces
    • Creation of new endpoints for the frontends
    • Implementation of import processes
  • Frontend
    • Extension of existing components
Technologies, tools
Java, SpringBoot, Spring BatchScheduler, Schedlock, Angular, PostgreSQL, JIRA, Confluence

Senior Developer

Healthware Kft

Pharmaceuticals & Medical Technology

10-50 team member

Our team was responsible for all aspects of the technological upgrade or new development of the in-house framework as well as the development of new functionalities to keep the system infrastructure up to date.

Tasks and areas of responsibility
  • Until 2022: Further development of existing Vaadin 7 based web applications
    • New view for Sankey diagrams
    • Development of the UI test infrastructure (RobotFramework, Selenium, containerization)
    • Development of the CI/CD (Subversion, Nexus, Maven, Docker)
  • Since 2022
    • Migration of the Vaadin app (with mixed front-end and back-end logic) to new technology stack with Angular and Spring-Boot
    • Business OO modeling (Hibernate)
    • Migration of backend functionalities (from Vaadin) to Java/Spring
    • Development of new backend functionalities
    • Development of the RESTful interface for the Angular web interface
    • Introduction of Kafka to perform data synchronization between remote sites
    • Introduction of a containerization infrastructure with the help of Docker Swarm - both for test and production environments
    • Development of configuration and build management (GitLab, Maven, Nexus, Jenkins, Docker, Ansible)
    • Creation of automated CI/CD pipelines with Git, GitLab, Jenkins and Maven to simplify operations
    • Integration of various 3rd party services (Keycloak, RStudio, ShinyProxy, Minio, OnlyOffice, Jupyter, Oracle APEX)
    • Introduction of SW development methodologies for the developments in R language: the company had no rules for R development, so the methodologies learned from Java development were taught here: shared R packages, dependency management (“renv”), version control (SVN, GIT), CI/CD operations (Jenkins, Docker)
Technology, tooling:
Java, JEE, Spring, REST, Angular, ORACLE, Hibernate, JPA,
Apache Kafka, Tomcat, Eclipse, XML, GitLab, Jenkins, Ansible, Maven,
Nexus, Docker Swarm, Traefik, Portainer, JIRA, Keycloak, Confluence, R, ShinyProxy, Oracle APEX, Minio, RobotFramework, Selenium

Container-Technology consultant

Pharmaceuticals & Medical Technology

10-50 team member

Our team has set up a Docker Swarm-based test and production environment at the customer's site to develop and run Shiny applications.

Tasks and responsibilities
  • Setup of complete test- and production system
  • Configuration of images for container virtualization
  • Independent development of software architectures for container-based application deployment
  • Implementation of container technology and orchestration of containers in a cluster
  • Independent error analysis and troubleshooting
  • Documentation of all measures taken 
  • Update and ongoing updating of the software and runtime environment used
  • Training of employees on site at the client's premises

Technologies, tools
Ansible, Docker Swarm, Traefik, Portainer, ShinyProxy, R, MySQL, GitLab

Senior Software Developer Team Lead

Logit Kft.
Developing an intranet application for a mobile provider in Austria, to be used by the customer support and systems administrators.
The goal is to provide a user interface where all settings of all backends can be seen and managed.

Tasks: leading a team of UI-development
Tools: GWT, GXT, Apache CXF, WebServices, Servlets, EJB 3.0, Apache Maven, SVN, Jira

Senior Software Developer Team Lead

Logit Kft.
Developing an internet application for a mobile provider in Austria, to be usedby companies owning multiple SIM-Cards.
The goal is to releaf the CustomerSupport of the mobile provider, that everyone can self-manage his mobilesubscription configuration.


Tasks: leading a team of UI-development
Tools: Java Swing (Applet), GWT, GXT, Apache CXF, WebServices, Servlets, JPA,Hibernate, EJB 3.0, Selenium, Apache Maven, SVN, Jira,

Co-Founder, Lead Developer

SynIQ Kft.

Pharmaceuticals & Medical Technology

< 10 team member

In this project, the control of a medical device was realized. The device is controlled by a Siemens PLC. The control is enabled in a web-based application that communicates directly with the PLC. The PLC writes the recorded event entries to a database via its own protocol, from which the data can be retrieved for analysis and reporting.

Tasks and responsibilities:
- Implementation of the PLC code (ladder diagrams)
- Implementation of the web application (vue.js)
- Implementation of the backend application (Spring Boot, PostgreSQL)
- Implementation of UI tests. Purpose: Repetition of long sequences, whereby both SW and HW (e.g. actuators, valves, etc.) are actually tested (RobotFramework, Selenium)
- Implementation of configuration scripts to install/update/configure the software on the Linux PC (Ansible)


Technologies, tools:
Java8, JEE, SpringBoot, REST, Angular, PostgreSQL, Hibernate, JPA, Eclipse, Jenkins, Ansible, Maven,
Nexus, JIRA, Confluence, RobotFramework, Selenium

Co-Founder, Developer

Logit Kft.

Internet & IT

< 10 team member

WHAALE (http://www.whaale.com) brings multiroom audio through Airplay to your mobile device (iOS and Android).
A team of 3 young (and not so young) developers made it with love and morethan 1.5 man-years of development.

Tools: Java, Eclipse, Objective-C, XCode, SVN, GIT, JIRA

Co-Founder, Developer

SynIQ Kft

Industry & Mechanical Engineering

< 10 team member

In diesem Projekt wurde ein modularisches Synthese-System erstellt. Sowohl die Hardware-Steuerung (Arduino) als auch die Java FX Benutzeroberfläche wurden aufgebaut. An der Benutzeroberfläche war es möglich aus beliebigen statischen (Kapillare, Behälter, etc.) und dynamischen (Spritzenpumpe, Ventile, etc.) Komponenten eine Synthese aufzubauen, die Synthese-Schritte zu bestimmen, simulieren und ausführen lassen.

Aufgaben- und Verantwortungsbereiche:
  • Implementation der Hardware-Steuerung (Arduino)
  • Implementation der Standalone-App (JavaFX)
    • Drag&Drop
    • Animation (Live und Simulation) der Bewegung von Flüssigkeiten

Technologien, Werkzeuge:
Java8, Java FX, Arduino IDE, Maven, Nexus, JIRA, Confluence

Co-Founder, Developer

Logit Kft.
The CAVU (http://www.cavu.io) app lets you fly with your DJI-drone using a VR-Headset and your mobile phone.

Tools: Java, Android Studio, DJI SDK

Senior Software Developer Team Lead

Logit Kft.
Development of a building-automation-system, specially for the fire- and intrusion detection.
Tasks: sw-architecture, leading a team of 4-7 developers, software development

Tools: Java, EJB 3.0, JMS, ActiveMQ, PostgreSQL, Eclipse RCP, SWT, Maven, CruiseControl, Subversion, JIRA, TRAC

Senior Software Developer Team Lead

Logit Kft.
Development of a passenger information system for the dutch railways.

Tasks: technical lead of specific modules, integration, development
Tools: Java Swing, WebLogic server, JMS, EJB, Spring, Hibernate, Oracle, CruiseControl, ClearCase, ClearQuest, RequisitePro, TRAC

Project Lead

Logit Kft.
Development of a client-application to manage data of marshalling yards.

Tasks: analysis, specification, software-architecture, development
Tools: .Net Framework, C#, MySQL, Visual Studio .Net, Rational XDE, Visual, SourceSafe, ClearQuest, Requisite Pro

Software Developer

Logit Kft.
Developing a portalsystem for achitects, based on PHP and MySql.
Self-written Java Template-Engine for caching of HTML-Templates.

Tools : Apache Webserver, PHP Module, MySql Database, Java for the Template-Engine.

Software Developer

Gacsal Software KEG.
Developing a Java API for a microchip-manufacturer. With this API the
managing of semiconductor data in large quantities is possible.
Technology: Core Java (IO, Collections, Memory-Management), Log4J.

Software Developer

Austrian National Railways
Programming of an application for the Austrian National Railways (ÖBB), for
administration of data of freight cars.
Task: creating a Swing-client in Java from scratch, which communicates with Corba-calls with the backend.

Tools: Java Swing, Inprise Visibroker, Toad, PVCS, Microsoft Visual Sourcesafe.

Software Developer

Developing an XML-based editorial-, content management- and
publishingsystem for large mediacompanies in Germany.
Task: developing an import-module, which enables the import of various XML-
objects (articles, images, flash files, etc.) into the CM- and editorialsystem, and
if required these objects are automatically published to the portal-system.

Tools: JSDK1.3, Apache Tomcat, Xalan, Xerces, XSLT, JSP, Servlets, Oracle 8, SQL-clients, CVS (Linux).

Software Developer

Sports betting company in Austria
1.
Development of an intranet-application ("Web-Reports") for a sports betting
company in Austria. This application gives reports about the business-flow of
the company. Functions: Creating of HTML report tables, possibilty of dataexport,
user authentication and authorization, session-management, multilanguage
frontend.

Tools: Oracle DB, JDBC, Tomcat, Servletmill, JGL, Log4J, Freemarker, Apache, SQL

2.
Development of an Internet-application ("Property-Tool"), which helps you to
edit and manage the configuration files of client computers (about 100 pcs.) in
the bet-offices.

Tools: Freemarker, Tomcat, Apache, JGL.

3.
Programming of a client application in Java for the administration of offers
for sportbets of a sports betting company. This application is used by the
bookmakers.

Tools : Oracle, Powertier application Server, Swing, Reflection , Log4J, EJB, SQL.

Junior Software Developer

Lufthansa Systems Hungária
Bugfixing and developing of the Internet-sites, coding of a B2B Marketplace Startup in Hamburg.

Certificates

Ethical Hacker

Robot Dreams Hungary

2026

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