Robert Skarwecki

Professional Summary

Highly qualified and experienced Senior Software Developer with over 16 years of experience in designing, developing, and maintaining complex software solutions. Expert in Java, with a strong background in backend development. Proven track record in conducting code reviews and ensuring adherence to clean code principles. Passionate about continuous education and staying updated with the latest technological advancements.

Technical Skills

• Operating Systems: UNIX variants (MacOS, Linux, Solaris), Windows
• Programming Languages: Java, C#, C++, C, Golang, Python
• Development Tools:
  • Java IDE: IntelliJ IDEA, Eclipse
  • Java Toolstack: Maven, Ant
  • Java ORM: Hibernate 3, Cayenne 2, JPA
  • Java XML Frameworks: JDOM, JAXB, JPA, Xstream, Xerces, JAXP, Xalan, JAXP
  • Native APIs from Java: JNA, JNR-FFI
  • Spring Framework, Spring Boot
  • Quarkus
  • Parser Generator: ANTLR
  • Installer Generator: Install4j
  • Unit Tests: jUnit, Mockito, BDDMockito, Moq, NUnit
  • GNU Toolstack: Make, Autoconf
  • Microsoft Toolstack: Visual Studio 2017, Team Foundation Server
  • Rational Tools: ClearCase, ClearQuest
  • Web Servers: Apache Tomcat 7, Apache HTTPD
  • Oracle SQL Developer
  • Dependency Injection: Spring, Guice, Castle, Unity
• Software Versioning: Git, Subversion
• Databases: Oracle, DB2, MySQL, PostgreSQL
• Tools & Platforms: ArgoCD, Docker, Helm, Kubernetes, Jenkins
• Cloud Services: AWS, Azure
• Software Development Methods: Agile, Scrum, DevOps

Product Knowledge

• Groupware/Office Communication: Microsoft Office, OpenOffice, LibreOffice, Apple Pages
• Application and Web Servers: Apache HTTP Server 1.3-2.0, Apache Tomcat 4-7, IMB HTTP Server, IBM WebSphere Portal Server, JBoss Application Server, IBM WebSphere Application Server 4.0-6.0, SAP AS 7.20 CE (NetWeaver)
• Provisioning: Sun N1 SPS 5.0-5.2
• Others: BIND 8/9, Samba 2.2, Squid 2.3/2.4, Electronic Health Card, Gematik, NeuroTechnology Biometric SDK, INTERPOL MIND, Cognitec FaceVACS

Education

Diploma in Computer Science (University of Applied Sciences)

University of Applied Sciences Heilbronn

Period: 09/2000 – 09/2024

Thesis Topic:Design and Development of a Generic Tool for Developing Domain-Specific Languages and Prototyping Language Extensions

Projects

02/2024-Present - Green Bond Reporting

• Description: The implementation of EU requirements necessitates the creation of extensive reports. The required data is maintained in a variety of existing and newly added internal banking systems. The data is consolidated, enriched, and sent to other systems via Kafka.
• Technologies Used: Java 18, Azure Blob Storage, ArgoCD, GH Actions, GitHub, Kafka, IntelliJ IDEA 2023.2.5 Ultimate, Docker 4.24.0, Kubernetes 1.27.2, Helm
• Client: Nord/LB
• Responsibilities:
  • Further development of five existing microservices
  • Design and creation of new microservices using hexagonal architecture
  • Migration of existing microservices to hexagonal architecture
  • DevOps: Administrative tasks in the Azure cloud
  • Introduction of end-to-end and integration tests for existing microservices
  • Definition of REST APIs via OpenAPI and implementation using Spring Boot
  • Integration of tests with Kafka
  • Creation of Kafka consumers and producers

09/2023-12/2023 - Digitization of Banking Processes

• Description: Three interlinked business processes for real estate valuation in a state bank need to be digitized. The BPMN and DMN diagrams provided by the business unit are prepared for execution in Camunda and the service tasks are implemented. Asset data is read from third-party systems, including SAP R/3, and updates are made. The correctness of the implementation is ensured by Given-When-Then tests.
• Technologies Used: Camunda 7.1, OpenAPI, Java 17, IntelliJ IDEA 2023.2.5 Ultimate, Docker 4.24.0, Kubernetes 1.27.2, Helm, ArgoCD, SAP R/3
• Client: Nord/LB
• Responsibilities:
  • Integration of BPMN and DMN models into Camunda; including some syntactic adjustments
  • Definition of service tasks based on BPMN
  • Implementation of service tasks based on descriptions in Jira tickets
  • Covering the functionality of service tasks with unit tests
  • Integration of third-party systems such as SAP using OpenAPI
  • Customization and extension of third-party mock servers
  • Integration of SSL certificates in Docker containers
  • Determining Camunda-specific methods for starting sub-workflows with specific data
  • DevOps tasks: Adjusting and extending deployment descriptions; carrying out deployments
  • Troubleshooting and bug fixing
  • Provision of REST APIs for the frontend and sister processes

09/2021-08/2023 - Payment Software

• Description: Context: In the context of credit card payments, terminals and other clients use REST APIs to communicate with a microservice developed (and further enhanced) by a small but highly effective team, which interacts with Hardware Security Modules (HSMs) in the background to perform the necessary cryptographic operations. The application runs in containers across multiple data centers.
• Technologies Used: Java 11, IntelliJ IDEA, macOS 13, Linux, Docker, Kubernetes, Helm, Lens, Jenkins, JIRA, Bitbucket, Git, Graylog, Grafana, Splunk, Postman, Spring Boot 2.7, Consul, Flyway, Resilience4j, JSON, Shedlock, Dius Pact, TestNG, Cucumber, Thales payShield 9000 & 10000
• Client: VISA
• Responsibilities:
  • Enhancement of the microservice
  • Migrating the microservice to hexagonal architecture
  • Conceptualization, proof-of-concept, and final implementation of a proxy-like migration tool that forwards REST calls to multiple data centers and monitors result equivalence
  • Design and implementation of contract tests using Pact
  • Creation of integration tests using Cucumber and necessary steps
  • Maintenance and extension of Jenkins pipelines
  • Low-level programming of Thales payShield HSM
  • Leading the conception and implementation of key re-encryption for the transition to another HSM

11/2021-04/2024 - Warehouse Management System

• Description: A proprietary warehouse management and logistics planning system used worldwide within the corporation has been gradually adapted to more modern technologies and approaches over time.
• Technologies Used: Java 8, Java 17, Ant, Maven, GitLab, Eclipse, IntelliJ
• Client: dm
• Responsibilities:
  • Designing a migration of the existing build process from shell scripts and Ant to Maven
  • Executing the migration
  • Maintaining and optimizing build pipelines in GitLab
  • Bug fixing
  • Advisory and consulting

06/2018-09/2021 - Diagnostic Software for Ophthalmologists

• Description:The various devices of a large German ophthalmology group store their images in a central archiving system. This includes a viewer component that is enhanced by disease-specific plugins used by ophthalmologists for diagnostic purposes and patient consultations. These plugins bring Java and partly .NET servers that perform professional analyses and create reports.
• Technologies used:.NET 4.6-4.8, Visual Studio 2017, IDEA Resharper, Nunit, Moq, Mockito, Maven 3, Java 8, Java 11, IDEA IntelliJ 2019 and 2020, Docker Desktop, Atlassian Jira, Bitbucket, Git, TeamCity, Remote Desktop, install4j 7-9, iText 7, Amazon EC2, JNR-FFI, JNA
• Client:Carl Zeiss Meditec
• Tasks:
  • Collaboration on three plugins with a focus on the backend
  • Collaboration on the archiving system itself
  • Java port of a C++ algorithm for wide-field measurement with extensive performance optimizations and implementation of an elaborate equivalence test to compare the original implementation with the port.
  • Integration of native libraries in Java using jnr/ffi and JNA
  • Main contact for the .NET servers.
  • Main contact for install4j based installers of the plugins and the archiving system.
  • Main contact for the reporting engine.

10/2014-05/2018 - Border Control System

• Description:Further development of a large Border Control System.
• Technologies used:.NET 4.6, Visual Studio 2015, Team Foundation Server 2015, Resharper 8, VISOTEC Expert 600 OEM, VISOCORE Inspect 1.9.4, NeuroTechnology SDK v9 and v10, Integrated Biometrics Fingerprint Scanner Columbo, Cognitec FaceVACS Entry, Magnetic eGate, Oracle 11g, Postgres 10, Microsoft IIS, jQuery, INTERPOL MIND, SOAP, XPath, WebSockets, WSQ
• Client:Veridos
• Tasks:
  • Development activities in both frontend and backend
  • Agile software development
  • Teamwork on shared code bases as well as independent design and implementation of isolated modules
  • Mainly integration of hardware components and database access layers

07/2012-03/2013 - Further Development of Cross-Section Products

• Description:Collaboration on the further development of an internal platform on which municipal applications are based, used in the offices of the City of Munich.
• Technologies used:Java EE, Microsoft SQL Server, JBoss, OSGi
• Client:AKDB - Anstalt für Kommunale Datenverarbeitung in Bayern

01/2012-05/2012 - Healthcare Portal with Smartcard Authentication and QES

• Description:Research and development of a technology demonstrator. The main challenges arose from the need to address card readers from Java applets running in the browser.
• Technologies used:JSF 2.1, Java EE 6, Tomcat 7, intarsys SignLive! 6.0, intarsys CloudSuite, Eclipse, ant
• Client:Giesecke & Devrient

03/2007-09/2014 - Card Application Management System (KAMS)

• Description:KAMS is a software solution for managing the entire lifecycle of electronic health cards. It is operated by health insurance associations and is responsible for the management of all legally insured persons in Germany.
• Technologies used:JBoss 4.2, J2EE 6, Cayenne 2, Oracle 10, DB2 9.7.5, Spring, JAXB2, SAP NetWeaver 7.20 CE, gematik, electronic health card
• Client:Giesecke & Devrient
• Tasks:
  • Further development of a large card application management system in multiple deployments.
  • Optimizations and bug fixes
  • Third-level support activities.
  • On-site deployments for configuration and setup optimization and general consulting

01/2007-02/2007 - Implementation of a Customer Self-Care Web Portal

• Description:A web portal allows the customers of a large energy supplier to report meter readings, download bills, switch tariffs and products, change installment payments, bank details, and other master data.
• Technologies used:Linux 2.6, PostgreSQL 8.1, Hibernate 3, Tomcat 5.5, JBoss 4, SAP R/3
• Client:Energy Supplier

06/2006-12/2006 - Administration of Application Platforms

• Description:
• Technologies used:IBM AIX 5.4, IBM WebSphere Application Server 6.0, IBM WebSphere Portal Server 6.0, IBM DB2, IBM HTTPD
• Client:Daimler-Chrysler AG
• Tasks:
  • Administration of a productive application platform for company employees
  • Performance analysis and optimization of internal enterprise portal applications
  • Creation of operational documentation
  • Design and implementation of application monitoring
  • Administration of a productive application platform for end customers as well as a test and integration environment
  • Installation and operation of operating systems (Solaris 10), web servers (IBM HTTPD) and application servers (IBM WebSphere Application Server 6)
  • Creation of tools for the automated setup and configuration of numerous application server nodes and distributed application deployments
  • Administration of a productive platform for capturing, consolidating, and reporting balance sheet figures
  • Operation of a complex enterprise application in multiple environments
  • Integration of middleware components in the Solaris Service Management Facility

07/2005-06/2006 - Implementation of a Data Center-wide Software and Service Provisioning System

• Description:A solution for software provisioning in the data center of an automotive manufacturer was designed and implemented, based on Sun N1 SPS as the base framework and executing system. The lifecycle of software components was separated from these in the form of a Control-SPS plugin. The actual software components were modeled in a fine-grained manner as SPS plugins and described using XML schemas. An admin frontend with a swing-based interface allows for the graphical composition of the software to be provisioned, its (re)configuration, (de)installation, and stopping and starting services. The allowed operations in the respective context are taken from the XSD description.
• Technologies used:Sun N1 SPS 5.0-5.2, Java 1.3, Eclipse 3.2, Jython 2.2, JAXP 1.3, Castor, XML, XSD, XPath
• Client:Daimler-Chrysler

06/2005-07/2005 - Further Development of the Website of a Securities Trading Bank

• Description:The website of a financial service provider is built with an in-house developed content management system. Besides general content such as news, financial calendar and download area, information on securities is also provided. The financial information is imported daily, the other data is maintained by the customer via an admin tool.
• Technologies used:Apache2, JK, JBoss/Jetty PostgreSQL, Eclipse, junit, ant, CVS
• Client:Baader Bank

05/2005 - Further Development and Optimization of the Resource Consumption of a Standalone Web Application for Displaying Log Files.

• Description:A standalone web application with an embedded web server displays log files and other text files. A flexible authorization concept allows individual users and user groups to be assigned log files and log file groups. Text replacements are defined using regular expressions to filter out passwords and other confidential information from the displayed files. Users can download the offered files individually or grouped as zip archives. By supporting GZIP compression, rotated log files can also be displayed or downloaded, with their contents also filtered. The application can handle multiple log files simultaneously, which are several gigabytes in size and do not fit into main memory.
• Technologies used:Java 1.4, Sun Solaris 5.8-5.10, AIX 5.2, Eclipse, ant, junit, CVS
• Client:
• Tasks:
  • Further development of existing application
  • Implementation of feature requests
  • Independent, proactive optimization of runtime behavior and memory requirements

08/2004-04/2005 - Administration of a Productive Application Platform for End Customers and a Test and Integration Environment

• Description:Installation and operation of operating systems (Solaris 8), web servers (IBM HTTPD, Apache) and application servers (IBM WebSphere Application Server 4). Creating scripts for monitoring the platform processes, generating environment-specific configurations, and switching between productive and standby environments.
• Technologies used:IBM WebSphere Application Server 4.0.5, Shell Scripting, IBM DB2, IBM HTTPD, Apache 1.3, Sun Solaris 8
• Client:Daimler-Chrysler

06/2003-03/2004 - Administration of a CMS-based Enterprise-wide Intranet Presence

• Description:Operation of content management systems (Vignette CMS 5 and 6) under Solaris 8. This included performing deployments of the maintenance application running in WebSphere and migrations of the database schemas.
• Technologies used:IBM WebSphere Application Server, Shell Scripting, IBM DB2, IBM HTTPD, Oracle 8i, Vignette Content Management Server 5 and 6
• Client:Daimler-Chrysler

04/2003-05/2003 - Synchronization of Data Stocks of a Worldwide Dealer Management System with Asynchronous Communication via MQSeries

• Description:Changes in the dealer system cause corresponding messages to be sent as XML files via MQSeries. These messages are picked up by a background process. This process then makes changes to the dealer data and dependent data in the LDAP directory service (Novell eDirectory) according to the received data. In case of errors, an email is sent to the responsible administrator. Due to the sometimes very complex processes, a self-developed framework based on jUnit is used for quality assurance. The customer defines acceptance tests, which are executed through this framework.
• Technologies used:Java, J2EE, MQSeries, LDAP, Eclipse, ant, CVS, junit
• Client:Daimler-Chrysler

03/2003-04/2003 - Transfer of Address Data from SAP to LDAP via EJB Server, SAP, and LDAP Connector

• Description:The address stocks managed by SAP R/3 are read out using JCO and mapped as EJBs in a JBoss Application Server. The addresses in the target system (LDAP directory) are also available as EJBs. An admin tool synchronizes the target system with the source system.
• Technologies used:Java, JNDI, JCO, JBoss Application Server, SAP R/3
• Client:Thinking Objects

10/2002-02/2003 - Implementation of a Website with a Self-developed Content Management System, Further Development of the System

• Description:The website of a financial service provider is built with an in-house developed content management system. Besides general content such as news, financial calendar and download area, information on securities is also provided. The financial information is imported daily, the other data is maintained by the customer via an admin tool.
• Technologies used:Java, JDBC, JBoss Application Server, PostgreSQL, JSP, EJB, idCMS
• Client:Baader Bank

09/2002 - Synchronization of Address Databases of PDAs with Company-wide Address Stocks

• Description:The addresses of employees, customers, and business partners are read from an LDAP directory via JNDI and saved as VCard files. Employees import these files into their PDAs to keep their contact information up to date.
• Technologies used:Java, OpenLDAP, Palm OS, JNDI
• Client:Thinking Objects

04/2002-08/2002 - Website of a Research Department

• Description:The internal corporate website of a research department was implemented in the corporate design of the company using JSPs.
• Technologies used:Java, JDBC, JSP, JRun Application Server
• Client:BMW

03/2002 - Design and Implementation of Caching for Database Queries to Improve Performance

• Description:An internet application was limited by the RDBMS being loaded with queries. A cache implemented in a COM component stored the query results for a period to reduce the frequency of database queries.
• Technologies used:Windows NT, ASP, DLL, COM, SQLServer
• Client:Bechtle AG

02/2002 - Connection of a Group of Clustered, Fail-safe Applications and Services to a Company-wide Monitoring System.

• Description:The performance data of WebSphere clusters is retrieved by an SNMP agent via HTTP(S) in the form of XML documents. These are translated into SNMP tables and queried by the company-wide monitoring system. For all measured values, maximum values can be defined whose attainment leads to status changes ("warning", "critical", etc).
• Technologies used:Java, IBM WebSphere Application Server 4, WebSphere PMI, SNMP (net-snmp)
• Client:Daimler-Chrysler

01/2002 – 02/2002 - Transfer of Telephone Cost Data from Telephone System to SAP via EJB Server and SAP Connector.

• Description:The monthly telephone cost billing in the company is done via a web frontend on the intranet. The data from the telephone system is converted to batch input files for billing private and business calls and then posted in SAP R3. For assigning phone numbers, personnel numbers, and cost centers, the personnel data stored in NDS/OpenLDAP is used. Login with different roles is handled by JBoss J2EE-compliant in NDS/OpenLDAP. A number of reports are provided via the web frontend as PDF files and secured so that past billings are also traceable.
• Technologies used:Java, J2EE Servlet (wingS), JBoss (EJB), NDS/OpenLDAP (JNDI), SAP/R3 (Batchinput)
• Client:Verlangshaus

08/2001 - 09/2001 - Installation and Tuning of a Company-wide Employee Portal

• Description:Installation and performance tuning of IBM WebSphere Application Server and IBM WebSphere Portal Server.
• Technologies used:IBM DB/2 and HTTP Server on Solaris, WebSphere Application Server and Portal Server on AIX.
• Client:Daimler-Chrysler

08/1999 – 04/2001 - Design and Implementation of a Document Management System in a Client/Server Architecture; System Administration.

• Description:The server-side web application built from servlets and JSPs offers a Java applet frontend. Users can upload, tag, categorize documents, and search using flexible criteria. Semantic relationships between categories and multiple category hierarchies, as well as fluid and fuzzy associations of documents to specific topics and categories, allow users to use their own evaluation and search criteria.
• Technologies Used:IBM DB2 EE, Apache HTTP Server, IBM WebSphere Application Server, Apache Tomcat on Linux, Visual Age for Java EE
• Client:InnoviData

Languages

• Deutsch – C2
• Englisch – C1