Hans Leidecker
Self-employed
Experience
Public Administration
- Developed web services for processing vehicle registrations (registration, transfer of ownership, deregistration)
- Implemented with Spring Boot, JMS (ActiveMQ), Oracle, Tomcat/JBoss, TomEE, OpenSearch
Insurance
- Migrated large data sets from Adabas with transfer to a REST interface in OpenShift
- Developed microservices for a data warehouse with interfaces to and from enterprise applications
- Developed REST services with HAL
- Implemented with Java 11, Spring, Oracle, OpenAPI, OpenShift, Kafka
Water Management Association
- New development of a multi-layer application for billing water consumption, sewer fees, disposal, installation orders, and integrated accounting software (general ledger, accounts receivable, accounts payable)
- Took over and prepared the data from the predecessor software
- Interface to E-Post; PDF archive
- Implemented with Java (Swing, Vaadin), RMI, JDBC; DB: MS SQL Server
Landscape and Gardening Company
- Ported software for invoicing, payment monitoring, cost accounting, payroll, and estimates to Delphi 8 for Windows XP and MS SQL Server 2000
- Implemented with Object Pascal (Delphi 8); DB: MS SQL Server
Deutsche Bahn
Developed and maintained (refactoring) the CFP timetable planning system based on the J2EE architecture: application components, interfaces; WebLogic, entity beans, message-driven beans, session beans, JAX-RPC, XSLT; Java rich client with Swing, RPC; DB: Oracle, DB2
Developed and maintained (refactoring) software for train monitoring (FplV-ZugUE/TraCE): client and server components with Swing, J2EE; CTG; batches and services for MVS/CICS; concept for authorization control with LSO; multi-tenancy; WebLogic with Spring, Ibatis/MyBatis, JAX-WS, JAXB, CTG, FTP; DB: Oracle, DB2, PostgreSQL
Designed, developed, and maintained/extended Hermes (HERM-LSO) for international exchange of train data: HTML/JSF, J2EE; CTG; Cobol batches, CICS online modules, XML parser, MQ Series; JBoss, Spring, Hibernate, CTG; DB2
Migrated the message hub Comgate to the Amazon cloud with Java, C, RTE, Python, shell; Tomcat 9, TradeXpress, Amazon DynamoDB, Connect:Direct, MQ Series
Maintained and enhanced CAM FplV with Cobol, MQ Series, DB2
New development of software to handle port orders for MVS/CICS (Natural, Adabas)
Modeled a data mart for punctuality measurements (PME); created technical interface and component specs; implemented ETL processes with Enterprise Architect, Java, JBoss, Spring, Ibatis; Java rich client with Eclipse RCP; DB: Oracle
New development of software for managing empty railcars (EWDS) with integration of a route optimizer developed in C++: Java, C++, JSF; JBoss, Spring, Hibernate, JNI; DB: Oracle
Technical upgrades: WebLogic up to 12.2.1, JBoss EAP up to 7.2.2, Java up to 11, OpenJDK, MQ Series; migration from RichFaces to PrimeFaces; processes: LSO-LSO, SD-LSO, GWD, GWVA, CDD, RST, PME, HERM-LSO, SVI, TraCE, ZuBA, CFP
Extended the LSO-LSO software with additional validations to protect against XSS attacks using Java and ESAPI
Grundstücks-Treuhand-Gesellschaft
- Porting a property statistics application to Windows NT with MS SQL Server 7
- Designing and setting up the database; porting data from Unix/ISAM to Windows NT
- Designing the user interfaces; modeling; implementation in C++
Bausparkasse
- Developing a home savings calculator for Windows 2000
- Modeling; developing and testing a platform-independent calculation core to simulate contract progress and contract changes
- Developing a test program for automated testing of the calculation core
- Implemented in Java
Versicherungsverband
- Independently developing a graphical editor for an object-oriented database
- Modeling; programming with Java (Swing) on OS/2, Unix, Windows
- Development on Windows using JBuilder2, on OS/2 with text editors
- Proprietary database access classes for other projects
Kugellager-Fabrik
- Developing software to monitor staff qualifications and to collect and analyze production data
- Windows network with OS/2 server, Windows 3.1x/NT/95
- Implemented in Object Pascal (Delphi)
Siemens-Nixdorf AG
- Assisting with porting the standard software for OPEL dealers from the Nixdorf Quattro system to Unix
- Using self-developed porting tools and database
Self-employed
- Development of a compiler to translate BASIC programs for Nixdorf Quattro into C for Unix
- Development of tools to convert files from Quattro format to Unix format
- Development of an index-oriented database for Unix to facilitate porting
- Development of a user-friendly print spooler for Unix
Skills
Programming Languages: Java, C++, C, Javascript, Cobol, Object Pascal (Delphi), Basic, Sql, Pl/sql, Rte, Python, Xslt
Frameworks: Java Ee (Ejb 1, 2, 3), Jax-rs, Jax-ws, Jax-rpc, Jms, Spring, Ibatis/mybatis, Hibernate, Swing, Java Fx, Vaadin, Eclipse Rcp, Jsf 2, Primefaces, Richfaces
Application Servers: Weblogic, Jboss Eap, Tomcat
Tools: Eclipse, Spring Tool Suite, Intellij Idea, Android Studio, Netbeans, Enterprise Architect, Eclipse Papyrus, Maven, Gradle, Ant, Liquibase, Jenkins, Artifactory, Clearcase, Clearquest, Git, Subversion
Industries: Car Trade, Building Societies, Construction Companies, Energy Utilities, Wholesale, Manufacturing, Public Administration, Transport Companies (Deutsche Bahn), Insurance
Databases: Oracle, Db2, Ms Sql Server, Postgresql, Opensearch, Object-oriented Databases, Amazon Dynamodb
Focus Areas: Independent Development Of User Software And Tools, Object-oriented Modeling/development (Uml), Refactoring, Java, Java Ee
Languages
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