Senior Software Engineer / IT-Consultant / Cloud Native Engineer

In the context of a conversion rate improvement project I have implemented various improvements to
the existing video/audio chat system. Among others:
* Implementation of a CallQualityCheck, which determines the quality of the connection based on
parameters such as upload/download speed, packet loss, jitter and other metrics
* Automatic video codec adjustment based on connection metrics

In addition, the following tasks were part of the daily work:
* Analysis and fixing of memory and performance issues
* Analysis and fixing of business critical issues in the production system
* Technical analysis, architecture design, documentation and POC's of new projects and/or
integration of external systems


Technologies: Icelink, WebRTC, Video Codecs VP8/VP9, Java, Play Framework, Spring Boot, iOS, AWS,
MySQL, REST Web Services

Design and development of the corporate website of GEFA Direkt GmbH based on the content management
system WordPress.
* Implementation of the design as WordPress theme
* Development of a job advertisement plugin as WordPress plugin
* Development of a Carousel-Plugin as WordPress Plugin
* Initial launch of the website
* Initial content insertion

Technologies: Wordpress, Bootstrap, HTML, Sass, JavaScript

Migration of a session system to Redis as Distributed Session Storage.
* Migration to Redis
* Load and performance testing
* Cluster and failover testing

Technologies: Java, Play Framework, Spring Boot, Redis, Jedis, AKKA, AWS

In the video server migration project, an existing video/audio chat system was completely
redeveloped based on the WebRTC framework IceLink 3.
* Design of a Signaling API
* Implementation of a SFU (Selective Forwarding Unit) based on Icelink 3
* Selective recording of video and audio stream and afterwards synchronization as well as
automatic merging of the tracks into one MP4 file with FFmpeg

Technologies: Java, Play Framework, Spring Boot, Microservices, Docker, WebRTC, IceLink, Video/Audio
Encoding, Akka, REST Web Services, FFmpeg, WireShark, HOCON, JUnit, SBT, Jenkins, Docker, ScrumBan,
AWS, MySQL

With the AutoIdent project, a product was developed that performs a fully automated identification
of a person based on machine learning / artificial intelligence services. Within the project I took
over the role as Tech-Lead for one of 2 teams. Team size approx. 10 persons.
* PoC development
* Microservices Architecture Concept
* Design of a uniform interface between backend systems and SDK's (Android, iOS and Web)
* Integration of ML/AI services like OCR, Face Comparison, Liveness Check and many more
* Consulting and verification of the technical possibilities of new features
* Code reviews and code merges of features developed by the team
* Guidance of the team members in the development of new requirements
* PoC to migrate from docker-compose to kubernetes

Technologies: Java, Play Framework, Spring Boot, Microservices, Akka, REST Web Services, HOCON,
JUnit, SBT, Jenkins, Docker, Scrum, Angular, Kubernetes, AWS, MySQL

Subproject GMUP: Within the scope of the project, processes and technical systems were analysed in
order to optimise them. From a technical point of view, special attention was paid to the
performance of individual systems and UI improvements. From a business perspective, processes were
simplified and optimized.
* Analysis and optimization of individual business processes
* Analysis and optimization of Java backend systems (Play Framework / Spring Boot)
* New development of individual parts of the agent portal with Angular

Subproject Wallet: Within the scope of the project a solution was developed that allows the creation
of an account during a video/eSign idents. This enables the signing of documents with a user
account, even without a renewed VideoIdent.
* Multi-tenant architecture concept, implementation and testing of the wallet micro service
based on the Play Framework / Spring Boot
* Integration into the video/eSign platform

Technologies: Java, Play Framework, Spring Boot, Microservices, Akka, REST Web Services, HOCON,
JUnit, SBT, Jenkins, Docker, Scrum, Angular, AWS, MySQL

Conception and development of a web application for the collection of personal data and integration
of external systems for video legitimization.
* Implementation of the web application with Angular
* Integration of external services via REST API
* Setup of the production environment

Technologies: Angular, HTML, SASS, PHP, Slim Framework

In order to replace the inconvenient post-ident procedure, an Identity-Verification-as-a-Service
platform was developed. Customers can identify themselves via video chat with a specially trained
agent with an identity document to open a bank account or similar.
In addition, contract documents can also be digitally signed during Videochat.
Focal points:
* Further development of the platform for scalability and high load requirements
* Development of web applications with JavaScript and Ember.js and extension of the native
mobile SDK's
* Microservices Architecture Concept
* Development of microservices with Java 8 and Play Framework / Spring Boot
* Cluster capability with Akka
* Asynchronous communication between Microservices with Akka
* Quality assurance and testing
* TestRobot: Extensive test automation with Selenium and phantomJS.
* Continuous Integration (CI) and Cloud Deployment-Prozess (GIT, SBT, Jenkins, Docker)

Technologies: Java, Play Framework, WebSockets, Microservices, Akka, REST Web Services, HOCON,
JUnit, SBT, Jenkins, Docker, Scrum, Angular, AWS, MySQL

Content of this project was the conception and realization of a portal for planning and execution of
promotions. Requirements workshops were held with the project stakeholders and a technical concept
was developed. Afterwards a technical solution concept was developed and the implementation was
carried out by a SCRUM team.
The technical implementation was based on a JEE-Liferay portal with Vaadin as GUI. The process logic
was implemented using BPMN 2.0 based on the inubit BPM Suite in conjunction with WebServices.
Several databases (MS SQL Server and IBM DB2) must be accessed in the backend.
* Requirements workshops
* Business concept and IT architecture
* SW Development BPM Process
* Consulting for surface development
* Data analyses
* Technical team leader:
* Definition of task packages
* Task Coordination

Technologies: Java / JEE, Vaadin, XML, Webservices, Liferay Portal, BPMN 2.0, Inubit BPM Suite, SQL,
MS SQL Server, AS400, IBM DB2

Conception and partial realization of an IoT platform for the collection and evaluation of
measurement data from vehicles (trains), as well as the monitoring and control of vehicle fleets
based on this data. Sensors are used to record measurement data on vehicles and transmit it to an
on-board unit via a CAN bus. Measurement data are e.g. position data, temperature values, wear data
of installed components, and much more.


Within the scope of the sub-project "Remote System Management and Software Deployment" a
multi-tenant management application was developed, with which:
* vehicles (trains) and vehicle fleets can be created and managed
* cloud servers (nodes) can be created and managed
* Software deployments in the form of OSGi bundles can be made from a central cloud repository
to the vehicles (on-board units) and the cloud servers. The software deployments were designed
to be fault-tolerant and rollback-capable.
The management application was implemented as a multi-layer JEE web application using Vaadin as
front-end technology.
* System architecture and software architecture
* Technical design incl. data model
* Software development JEE web application
* Software development of OSGi bundles
* Deployment-Prozess
* Test in laboratory environments with Raspberry as mobile units (OCU)
* Quality assurance and testing
* Execution of management demos

Within the subproject " Eco System" basic mechanisms for the IoT platform and the associated Eco
System were designed and implemented.
These mechanisms include:
* Messaging, Storage and Logging API
* Error Handling
* System functions
* Subsystem-Adapter
* GUI-Framework
* Reporting
Tasks in the project:
* Software Architecture
* Technical design
* Java / JEE software development
* Deployment-Prozess
* Quality assurance and testing

Technologies: UML, Enterprise Architect, Java /JEE, XML, Vaadin, WebServices, Messaging, JMS, SQL,
OSGi, Apache Karaf, Apache Aries, JUnit, git, Integrity, Maven, DevOps, Raspberry Pi, Onboard-Units,
SCRUM, Trello, PostgreSQL

Within the scope of the project, a Unified Sales Platform was developed, which enables a retailer to
handle the entire sales process from the collection of customer data, to the configuration of a
vehicle, to the delivery of the vehicle to the customer.
Technical requirements:
* sales process management
* Customer-Management
* Configuration of vehicles
* Offer-Management
* Contract-Management
* Order-Management
Technical challenges:
* Integration of many external systems
* Multi-client capability (Tenant+Tenantscope)
* Rollout in more than 6 countries

The project is handled according to the agile method Scrum and consists of 8 teams. One team
consists of 5 to 7 developers, 2 PO supporters and one IT PO and one business PO. The project
language is English.
As a software engineer I was part of the "customer" team. Which mainly deals with customer
management, customer visibility, business codes, activity management, SPL check (sanctioned-party
list check), business context and others.

Tasks:
* Conception and implementation of technical requirements
* Integration of external systems
* Create and maintain selenium and integration tests
* Analysis and evaluation of topics and user stories
* Participation in community of practices dealing with topics such as "Frontend Architecture"
and "Portal development"
* Error analysis and bug fixing
* Communication and coordination with interface partners
* Presentation of Sprint results

Technologies: JEE6 (EJB3, CDI, JPA, JSF, Rest, SOAP), Spring Framework, Primefaces, Oracle DB,
Mockito, Selenium, Restassured, Maven, Glassfish 3, Jenkins, Intellij IDEA, SVN, Confluence,
JavaScript (jQuery, Jasmine), SCRUM

In order to give customers a better overview of their existing point of a cashback system, a web
application was developed, which lists the transactions and received points. Additionally a mail
inbox functionality was developed.
* Development of the web application with AngularJS
* Development of a micro service with Spring

Technologies: AngularJS, Tomcat, Spring

The project focused on the automation of deployment and delivery processes of special software
development projects. The software development projects were based on the technologies Oracle 11g
database and IIS web server.
Tasks of the application:
* Monitor issue tracking systems and retrieve relevant information from these sources from
version management (VSS/SVN)
* Manage environments (databases/web servers)
* Creation of Builds
* Automated installation of builds
Tasks in the project:
* Creating and maintaining the project plan (cutting work packages, determining times, assigning
resources)
* Design and implementation of the application architecture
* Development of interfaces to applications like SVN, VSS, HP Quality Center 10
* Development of a web application with Struts
* Setup of the test and productive environments
* Execution of black box and usability tests

Technologies: Java 6, Axis 2 1.6, Struts 2.1, Ant, Tomcat 6, Eclipse, Enterprise Architect, SVN,
VSS, Oracle 11g