Java Full stack Developer

10/2021 – 10/2022

As a backend consultant, this is part of my daily work
Technologies:
Java, Eclipse, Hadoop, Spark, Scala (POC purpose only), Maven, Hibernate, VMWare, Derby, Ubuntu, Docker, Docker-Compose, Bash scripting (POC purpose only), Talend ESB, unit and integration tests , Windows, Linux , JDWP for remote debugging, Jprofiler
• Development of a SOA data storage service with Java and implementation in Talend ESB
• Creation of VMware Virtual Machines Ubuntu 21.10 and 22
• Installing Hadoop, Hive, Derby, and Spark
• Set up Spark as Hive's execution engine for faster queries
• Hadoop 2.7.3 and Hive3.1.2 version compatibility by adapting Hive
code for ACID transaction tables
• Review and creation of technical documentation for installing VMs
• Analyzes different ways of accessing Metastore
• Used Java Hibernate ORM API to create the Derby database schema
and populate the tables.
• Rerun and tested Hadoop and Hive Java APIs Linux installation
• Built Docker containers for Hadoop and Derby
• Docker Compose used for container orchestration.

Apache Hadoop, Apache Spark, Windows 8, Enterprise Service Bus, Docker, Hibernate (Java), Java (allg.), Scala, SOAP, Vmware, Linux Einführung

4/2019 – 9/2021

Genios offers an ElasticSearch-based search engine for German regional and business databases
My role in the project:
As a backend developer, this was part of my daily work
Technologies: Java, Groovy, Intellij , SpringBoot , Microservice, REST, SOAP, Elastic Search, XML, JSON, XML Parser SAX and DOM, LogStash , Kibana ( ELK Stack), Mongo, MySQL, Message Broker Morphium , Apache FreeMarker Template, Spring MVC, JQuery , Java Script (Frontend development only according to ticket requirements), multithread application, MAC, Linux, Jprofiler , HTML, CSS
• Extensive data processing from XML to Json with DOM/SAX parsers
• Thorough interaction with NoSql Mongo db to take advantage of
simplified JSON representation of data
• data modeling
• Upload publisher data daily after processing in Elastic Search
• Works on developing Job Execution Framework for backend using
technologies like Java 11.0 OpenJdk , Springboot Framework and
FreeMarker Template in MVC architecture for related internal frontend.
• Working on updating and maintaining backend and frontend of GBI
Genios web portal built with Groovy on Grails Framework and using GSP
for frontend webpages.
• Worked on Job Execution Framework (it works like Spring Batch)
• Working with REST APIs and HTTP client for partial data processing

Mongodb, Mysql, Java (allg.), Spring Framework, XML, Serviceorientierte Architektur, SOAP, Elasticsearch, Representational State Transfer (REST)

11/2017 – 11/2018

Within Scrum software development processes, the following modules were worked on:
Technologies : Java, Hibernate, Cassandra, Hazelcast IMDB, Feign Netflix REST Client, Hystrix Message Broker, Spring Retry, SpringBoot (intensive work), Eclipse, Git, Source Tree, Message Broker RabbitMQ, Junit, TestNG, Mockito, Windows, Linux , Nginx
• Forwarding: Defined REST API using Swagger.
• Developed a Feign based REST client that uses Rabbit MQ Message
Broker to listen on queues for data and uses REST API from backend to forward it to backend.
Provides Spring retry function and baffles call to REST API using CircuitBreaker for failover mechanism.
• HazelCast uses IMDG to share some data in a distributed environment.
• An XML-based parser was extended to parse some raw telemetric data
in flexible key-value manner, which was later sent to the REST server
using Forwarder.
• A log module was refactored and extracted from an existing project to
provide a clean implementation with Springboot acting as an independent REST server to read and write data on REST calls to the Cassandra backend.
• Code reviews done
• Also participation in a Scrum workshop

Java (allg.), Spring Framework, XML, Representational State Transfer (REST)

6/2014 – 5/2016

CTA-ACTL: Array Control - Cherenkov Telescope Array
Project Description: CTA's Array Control is a SCADA system that aims to provide control, monitoring and data acquisition for the Cherenkov Telescope Array.
My role in the project:
• TMCDB Port on MySQL, which previously only supported Oracle HSQLDB, TMCDB uses XML DB as a configuration database (CDB) that provides the schema for the corresponding tables in the Oracle and MySQL relational databases.
• Alarm client and logging client: Alarm and logging clients store alarms and logs in the NoSQL database, respectively. Customers also use Mongo DB's capping feature to prevent retaining data that has lost relevance.
• Code reviews done
• Presentation on OPCUA at the OPCUA Bootcamp in Milan, Italy.
• Lecture about TMCDB in the European Southern Observatory Garching
near Munich

Mongodb, Mysql, Hibernate (Java), Java (allg.), Junit, Swing (Java)

6/2010 – 6/2012

Technologies: VC++, VB, CVS, VMware, Windows
Project description : AFIS is an advanced fingerprint identification system that follows a three-layer architecture. Tier1 is matched server and feature database. Tier2 is a middleware that processes and routes requests from multiple Tier3 clients. Tier3 is the client system that provides the operators with the AFIS GUI.
My role in the project: Worked on Tier2 and Tier3. Performed maintenance for dozens of websites and developed new features as needed.

Visual C++

9/2008 – 6/2010

Shrutlekhan : Rajbhasha , Hindi speech recognition software
Project description: Shrutlekhan is a Hindi speech recognition system that can recognize different dialects of the Hindi language. It takes sound as input and converts it to Devnagari - text output.
My role in the project : Development of a tool that can pass the recognized text stream to any UI editing control in the operating system. The task was to connect to Windows and capture relevant system messages. Also the maintenance of the project performed .

Microsoft Foundation Classes (MFC), Visual C++