Robert R. - Further development of an internal application

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Szczecin, Poland

Experience

Feb 2025 - Present

7 months

Further development of an internal application

Fima Maschinenbau GmbH

Adapting existing functionalities, bug fixing and development of new features.
Multithreading, technical calculations in fluid dynamics, graphics, data import/export, reading data from measuring devices in separate threads.
Technologies: Delphi 12, FireDAC, parallel programming, multithreading, communication over IP and serial bus.
Own contribution: development, bug fixing, testing, documentation.

Jul 2024 - Apr 2025

10 months

Development of a data transmission system for ARM architecture

Maenken Systems

Development of a data transmission system for ARM architecture using Lazarus and client software with Delphi.
Technologies: Delphi, Lazarus, ARM, cross compiling, multithreading, REST, HTTP, Git, GitLab.
Own contribution: architecture, analysis, development, testing, documentation.

Jan 2024 - Dec 2025

2 years

Instructor

Werft der Bundesmarine

Conducted several courses on Delphi/Firebird (introduction, advanced, complex topics) for staff at a German Navy shipyard.
Designed and conducted the training, and consulted on database and software architecture issues.
Technologies: Delphi 12, FireDAC, Firebird.
Own contribution: training, consulting, idea generation.

Sep 2023 - May 2024

9 months

Development of a software system to optimize energy distribution in heating systems

MyWarm

Technologies: PHP, MySQL, Bitrix, Git, GitLab.
Own contribution: architecture, analysis, development, testing, documentation.

Jun 2023 - Feb 2024

9 months

Vienna, Austria

Consultant

Federal Ministry for Climate Action, Environment, Energy, Mobility, Innovation and Technology

Advised on architecture, performance, deployment and interfaces in Section V: Environment and Circular Economy.
Technologies: Java, Spring, OpenAPI, Python, Jira, Confluence, Camunda, GitHub, ITIL.
Own contribution: architecture, analysis, requirements analysis, new concepts, consulting, UX testing, documentation.

Feb 2022 - Nov 2022

10 months

Development of new features in Dispotafel

Real Estate Service Germany

Development of new features in Dispotafel - a tool for planning cleaning staff and service deployments. Documentation.
Design and redesign of the user interface.
Design and implementation of the SOAP client for the fee and commission calculator.
Definition of the WSDL file.
Database interface.
Data migration.
Technologies: Delphi 10, 11, Informix, Firebird, Java, Maven, SOAP, DevExpress, JCL, TMS, GitHub.
My share: development, testing, documentation.

Nov 2021 - Mar 2022

5 months

Lead Developer

Bayer CropScience

Further development of a mobile application and its backends for farmers. The app calculates quantities and application cycles of fertilizers and fungicides depending on crop types and regions.
Analysis of the existing solution and the backlog.
On the backend: replacing a monolith, implementing microservices.
On the frontend: adjusting the user interface according to product owner's requirements.
Implementation of a Kafka client.
Expansion of unit tests.
Bug fixing.
Handover of the project to a development team, supporting the team and documentation.
Technologies: Java, PHP, Spring/Spring Boot, Hibernate, Kafka, microservices, Liquibase, Maven, AWS, GraphQL, cloud, REST, JSON, XML, Git, GitLab, DevOps, CI/CD, Docker, JavaDoc, React Native, Agile, JavaScript.
My share: architecture, analysis, requirements analysis, testing, documentation, supporting the team in taking over development, leading, coaching.

Jun 2021 - Dec 2021

7 months

Lead Developer

ostermann.de

Project and implementation of an interface (microservice architecture) between the existing ERP system and a new version of the ERP. The interface should compare imported data and create a migration report.
Analysis of the data formats provided by the existing ERP system as a database table.
Design of the ORM models.
Design and implementation of a converter that imports the data and exports it to the new ERP.
Design and implementation of a backend application.
Expansion of unit tests.
Technologies: PHP7, Laravel, MySQL, Eloquent, PHPStorm, Java, Spring/Spring Boot, Spring Batch, Spring Cloud Stream, Kafka, Maven, microservices, REST, jQuery, JSON, XML, SCRUM, Agile, Git, GitHub, CI/CD, PHPDoc.
My share: architecture, analysis, requirements analysis, testing, performance and load testing, middleware implementation, documentation.

Jan 2021 - May 2023

2 years 5 months

Vienna, Austria

Configuration, customization, and testing of web servers, load balancers, and the CraftCMS environment

Vienna City Office

Creating documentation, consulting on architecture and performance.
Technologies: PHP7, Laravel, Nginx, RedHat Linux, CraftCMS, Docker, Kubernetes, Terraform, Jira, Confluence, GitHub, ITIL.
My share: architecture, analysis, configuration, consulting, testing, documentation.

Feb 2020 - Present

5 years 7 months

Internal/personal project, smart home with Arduino and Raspberry Pi

Development of a central server and multiple clients for a smart home system.
As a sandbox for new technologies: architecture, development, deployment, and testing of clients, servers, and frontends in a heterogeneous environment with an event-driven architecture.
Database architecture, optimizing database queries.
Technologies: Java, Spring/Spring Boot, Spring Cloud Stream, Symfony 7, Yii2, Delphi Berlin, Angular, TypeScript, jQuery, Groovy, microservices, Maven, MySQL, Firebird/Interbase, FireDAC, Kotlin, UML, REST, JSON, XML, Twig, PHPDoc, Arduino C, Arduino FreeRTOS, Lumen, Hibernate, Kafka, MongoDB, MQTT, Symfony Workflow, Symfony Messenger, IBM MQ, AWS, Grafana, Camunda, CI/CD, design patterns.
My share: architecture, requirements analysis, development, testing, TDD, BDD, deployment, maintenance, DevOps, Terraform, Docker, Kubernetes, preparing and maintaining pipelines for tests and roll-out.

Feb 2020 - Sep 2022

2 years 8 months

Hanover, Germany

Lead Developer

Zentralen Polizeidirektion Niedersachsen

Upgrading a legacy system (managing internal resources, applications, events, data transfer and backup, reports) from PHP 5 to PHP 7.
Static codebase analysis. Identifying code areas that need refactoring.
Refactoring.
Implementing a new database interface, adjusting external interfaces.
Designing and implementing objects to replace existing logic.
Replacing global variables.
Unit tests, integration tests, and bug fixing.
Security identification management via a REST API.
Documentation.
Technologies: PHP 5+7, internal MVC framework based on Laravel, MySQL, Security Identification Manager, Eloquent, PHPStorm, Jenkins, REST, JSON, XML, Scrum, Agile, Git, GitLab, SVN, SVN hook scripts, PHPDoc, DevOps, Docker, Kubernetes.
My contributions: architecture, analysis, requirements analysis, upgrading from PHP5 to PHP7 of a legacy system, refactoring, testing, TDD (test driven development), middleware implementation, migration, documentation.

Dec 2019 - Jan 2020

2 months

Backend development of a retail platform

aboutyou.com

Analyzing weaknesses of the transaction system and designing countermeasures.
Developing a module to calculate delivery time based on order data, delivery addresses, and carriers.
Developing a module for Google Analytics.
Expanding unit tests.
Technologies: PHP 5+7, internal MVC framework based on Symfony, microservices, OAuth2, MySQL, PHPStorm, AWS, cloud, REST, Python, Docker, Kubernetes, Symfony Workflow, JSON, XML, Scrum, Agile, Git, GitLab, Grafana, PHPDoc.
My contributions: analysis, refactoring, development, debugging, testing, unit tests, performance and load testing.

Jan 2019 - Nov 2019

11 months

Hamburg, Germany

Development of a service management platform

Stulz

Developing an import tool for the customer database.
Developing new features for the deployment calendar.
Developing a REST client.
Implementing a tracking module and unit tests.
Technologies: PHP 7, Laravel, MySQL, Eloquent, microservices, PHPStorm, Bootstrap, REST, JSON, Angular, TypeScript, jQuery, Docker, XML, Scrum, Agile, Git, GitHub, PHPDoc, design patterns.
My contributions: analysis, refactoring, development, middleware implementation, Scrum coaching.

Sep 2018 - Dec 2018

4 months

Development of a retail rewards management platform

skon.de

Developing a price and rewards calculator that serves as a REST server.
Implementing unit tests.
Technologies: PHP 7 (PHP 7.2), MySQL, JavaScript, Angular, TypeScript, Bootstrap, PHPStorm, REST, JSON, XML, OAuth2, Scrum, Git, Bitbucket, Docker, Kubernetes, internal framework built on Symfony 4, Twig, PHPDoc.
My contributions: analysis, refactoring, development.

Sep 2018 - Nov 2018

3 months

Lead Developer

agrora.market

Developing a platform for agricultural trading. A prototype had to be turned into a live version in a short time. Platform users post their buy/sell offers for agricultural products (grains, oilseeds, etc.). Customers negotiate terms online and finalize contracts.
Architecting and developing the platform, both frontend and backend.
Developing a REST client for exchange server APIs.
Implementing unit tests.
Technologies: PHP 7 (PHP 7.2), MySQL, microservices, JavaScript, Angular, TypeScript, jQuery, Bootstrap, PHPStorm, Python, UML, REST, JSON, XML, Scrum, Git, GitHub, Docker, Kubernetes, Symfony 3+4, Twig, PHPDoc, DevOps, Selenium, architecture patterns, design patterns.
My contributions: architecture, requirements analysis, refactoring, development, testing, unit tests, UX tests, setting up CI/CD pipelines, Scrum coaching.

Sep 2018 - Oct 2018

2 months

Co-development, refactoring, and bug fixing of the existing backend system for shop billing

mobilcom-debitel

Migration of the codebase from Delphi 5 to Delphi Berlin.
Development of modules for price calculation, stock level calculation, and data/database interface synchronization between the central server and individual shops.
Technologies: Delphi Berlin, Delphi 5, Firebird, IB Expert, UniDAC, FastReport, C#, .NET, XML, SOAP, GitHub, JIRA, SCRUM.
My contributions: analysis, refactoring, development.

Jun 2018 - Aug 2018

3 months

Co-development and refactoring of the existing backend system for health insurance billing

optica.de

Development of modules that deliver data about provided services as XML files to a server.
Refactoring a monolith towards microservices.
Implementation of unit tests.
Technologies: PHP5, Zend, MySQL, JavaScript, Angular, TypeScript, Redmine, SVN, SVN hook scripts, PHPStorm, REST, JSON, Docker, Kubernetes, refactoring (from monolith to microservices), XML, SCRUM.
My contributions: analysis, refactoring, development, maintenance of legacy code.

Apr 2018 - Jun 2018

3 months

Development and refactoring of the existing backend system for credit consulting

finanzcheck.de

Development of a price and interest comparison platform for banking products.
Technologies: PHP5, Symfony3, MySQL, Propel, MongoDB, Grafana, JavaScript, Jira, git, Bitbucket, PHPStorm, REST, JSON, XML, SCRUM, Docker, Kubernetes, PHPDoc.
My contributions: analysis, refactoring, development.

Mar 2018 - May 2018

3 months

Lead developer

yas.life

Design and architecture of a multi-tenant backend environment for a fitness app.
Design and architecture of a multi-tenant environment.
Implementation of a guideline for the development team.
Database adjustments.
Support for the development team.
Technologies: Java, Spring, Spring Boot, UML, Swing, microservices, Hibernate, MongoDB, Grafana, OAuth2, Jenkins, CI/CD, Jira, Git, GitHub, Docker, AWS, cloud, Kubernetes, REST, JSON, SCRUM, Maven, JavaDoc, architectural patterns.
My contributions: architecture, requirements analysis, refactoring, TDD (test-driven development).

Sep 2017 - Mar 2018

7 months

Team member

DBConnect

Development, refactoring, and bug fixing in a booking/tracking system for car sharing and city bikes.
Implementation of a price calculator (as a SOAP server).
Technologies: PHP4, PHP5, MySQL, Jira, SVN, git, PHPStorm, JavaScript, TypeScript, REST, XML, JSON, Docker, Smarty, SCRUM.
My contributions: development, code reviews, analysis, refactoring (from monolith to microservices), maintenance of legacy code, tests, unit tests, UX tests, debugging.

Oct 2016 - Aug 2017

11 months

Backend Developer

AirBerlin

Member of a backend development team. Development, refactoring, optimization of a new version of a booking/tracking system for airports (shopping, booking, payment).
Highly intensive use of SCRUM/SAFe.
Development of interfaces to external systems: Amadeus, Comarch, Sixt.
Server-side programming of interfaces for the frontend.
Import/export/recalc of passenger loyalty cards using batch programming and cron jobs.
Security Identification Management via a REST API.
Technologies: Java, Spring/Spring Boot, Spring Batch, Swing, Hibernate, Kafka, Elasticsearch, microservices, Jira, Jenkins, git, PHP, PHPStorm, Perl, cron, UML, REST, XML, JSON, SOAP, RIAK, Redis, OAuth2, Security Identification Manager, Angular, TypeScript, JavaScript, Splunk, Google Analytics, SCRUM, SAFe Scrum, JavaDoc, Maven, Docker, Kubernetes, design patterns.
Own contributions: architecture, development, code reviews, analysis, refactoring, legacy code migration, tests, unit tests, performance and load tests, Selenium, debugging, 3rd level support.

Apr 2015 - Sep 2016

1 year 6 months

Lead Developer

rieber.de

Development of an intelligent food-flow system according to HACCP rules.
The backend services of the system are accessible through a browser cockpit (for desktop clients) and iOS/Android apps (for mobile clients).
The current version of the cockpit is being refactored with AngularJS within the responsive design paradigm.
Another group of services are the asynchronous calls to various sensors that report the temperatures of the thermoports (isothermal containers used to transport the meals).
A Symfony controller provides a REST interface.
Data is transferred either in XML or JSON format.
Frontend adjustments and new features using HTML, CSS, JavaScript.
Preparing the pipelines for roll-out.
Technologies: PHP (PHP5), Symfony2 (2.5, 2.6), MySQL, microservices, Jira, Jenkins, Docker, Kubernetes, CI/CD, git, PHPStorm, UML, Smarty, REST, XML, JSON, AngularJS, JavaScript, Ajax, HTML, CSS, OAuth2, PHPDoc, DevOps, Azure, cloud, responsive design, design patterns, architecture patterns.
Own contributions: architecture, creating project plans, code reviews, analysis, refactoring, legacy code migration from monolith to microservices, tests, debugging, preparing, testing and maintaining CI/CD and Docker pipelines, scrum master, scrum coaching.

Jan 2015 - Apr 2015

4 months

Developer

modix.de

Various development tasks in the client's system.
Technologies: PHP, Zend, MySQL, Jira, svn, Zend Studio, Docker, Smarty.
Own contributions: development, code reviews, analysis, refactoring, legacy code migration, tests, debugging.

Oct 2014 - Dec 2014

3 months

Developer

clickbus.de

Co-development of a price comparison platform and a booking portal for long-distance bus travel within an international team (Germany, Brazil, Poland, Turkey).
Reading price lists of various bus companies and operators via their REST and SOAP interfaces.
Development of new features, debugging, code reviews.
Technologies: PHP, Symfony2, MySQL, OAuth2, LDAP, Twig, PHPUnit, PHP Code Sniffer, jQuery, SOAP, REST, microservices, Docker, Kubernetes, Docker, Jira, SCRUM, PHPDoc.
Own contributions: development, refactoring, debugging.

Jun 2014 - Sep 2014

4 months

Migration of a trading tool

modix.de

Migration of a trading tool (about 26,000 PHP scripts) for new and used cars from ISO to UTF-8.
Adapting the relevant functions in the code and the interfaces to external systems.
Technologies: PHP4+5, Zend, MySQL, Jira, LDAP, REST, svn, Zend Studio, Smarty, Docker.
Own contributions: code reviews, analysis, refactoring, legacy code migration, tests.

Jan 2014 - May 2014

5 months

Karlsruhe, Germany

Backend Developer

Flagbit.de

A billing system for energy supply and the electricity and gas market (quantum.de + municipal utilities).
Entering factors relevant to the price lists and retrieving the price series (prices were calculated in 15-minute intervals for specific time periods, like months) via a REST interface.
The documentation for the interface was created with swagger.io.
Technologies: PHP, Symfony2, Doctrine, YAML, Twig, REST, Swagger.io, Angular, Typescript, Jenkins, git, Jira, plan.io, Docker, PHPStorm, PHPDoc, sphinx, confluence.
Own contribution: development, testing.

Dec 2012 - Nov 2013

1 year

Development of an iOS app for a naturopathic practice

First encounters with the mobile world.
Design and implementation of an app for scheduling patient visits (calendar).
Technologies: Objective-C, iOS, OOD/OOP, SCRUM, Xcode.
Own contribution: SCRUM member, implementation.

Nov 2012 - Nov 2013

1 year 1 month

Wolfsburg, Germany

Report generator for a module database

Volkswagen AG

Concept and architecture of the solution.
Defining reports with YAML scripts, engine in PHP5; graphically mapping the structure of modules, module families, sub-assemblies, and process flows.
Implementation of a PDF generator.
Implementation of a REST client to transfer the generated files to a DMS server (Document Management System).
Operating an archive of module images.
Technologies: OOD/OOP, PHP, MySQL, YAML, UML, REST, regular expressions, Wiki, OTRS, SVN, SVN hook scripts, archive (internal VW DMS).
Own contribution: architecture, implementation, testing.

Nov 2011 - Oct 2012

1 year

SCRUM Member

fabrykagier.pl (game factory)

Universal interface between the frontend (Flash, Unity3D or other frontend technologies) and social portals (Facebook, Google+).
Defining the game assets (items, virals, quests, tutorials).
Measuring the backend load.
Automatic startup of cloud servers.
Modules for monetizing the games.
All services of the interface were accessed via REST.
Architecture and development of a very lightweight MVC framework for performance.
Central controller of the framework was the entry point for REST calls.
Greenfield project.
Technologies: OOD/OOP, UML, PHP5, Apache, nginx, REST, MVC, JSON, MySQL, MongoDB, Memcached, Jenkins, SVN, GitHub, TDD (test driven development), unit tests, Facebook API, HTML, CSS, SCRUM, Eclipse, NetBeans.
Own contribution: concept, architecture, implementation.

Mar 2010 - Mar 2011

1 year 1 month

Backend Developer

vivio.pl

Backend developer for a Facebook game project.
Architecture and implementation of the backend with PHP and Zend, designing a sharded database in the Amazon cloud.
Implementation of communication between the frontend (Flash) and the backend part using AMF.
Technologies: OOD/OOP, PHP, Zend, Apache, SQL, REST, AWS, EC2, sharding, AMF, UML, Basecamp, SVN, SCRUM, Eclipse.
Own contribution: SCRUM member, architecture and implementation of the backend, testing.

Feb 2009 - Mar 2010

1 year 2 months

Project of a workflow system for a lab

Project of a workflow system for a lab that carries out tests for the construction industry.
Technologies: OOD, UML.
My contribution: Architecture.

Mar 2007 - Mar 2010

3 years 1 month

Szczecin, Poland

Project management

espol.pl

Collaboration in a team on the design, implementation and maintenance of a web-based billing system for triple-play billing (about 20,000 customers).
Generating quotes, contracts, invoices (internet, IPTV, VOD, VoIP), importing bank statements, creating configuration files for access servers and access points; a report generator; access and shape control via RADIUS; mapping the topology.
Technologies: OOD/OOP, PHP4+5, MySQL, HTML, CSS, JavaScript, Wiki, Redmine, UML, design patterns, Smarty, SVN, MVC, RADIUS, REST, SOAP, XML, Eclipse.
My contribution: Concept, architecture, implementation, testing, maintenance, project management.

Jan 2006 - Dec 2007

2 years

Consultant

Institute for Paleobiology

Consulting on building a database of animal species.
Existing archives had to be integrated and a new one created.
The main goal was to create an architecture that ensures the data remains readable and usable over decades.
This was to include a feature for continuous migration to new file and database formats.
Technologies: DMS, various file system archives, MediaWiki, migration scripts.
My contribution: Design, architecture, consulting.

Jan 2006 - Dec 2006

1 year

Development of a content management framework based on IIS/ISAPI

Technologies: Delphi, Pascal, IIS.
My contribution: Development, testing.

Jan 2006 - Dec 2006

1 year

Szczecin, Poland

Porting the system for general practitioners to PHP5

Porting the system for general practitioners to PHP5: patient database, calendar backend, digital patient record, report generator.
As part of a reorganization of general practitioners' practices in Poland, private clinics were established. Previously, clinics were managed by municipalities.
In my city (Stettin/Szczecin, population about 400,000) I took the archived patient database from a mainframe, converted it, split it, and stored it in the databases of each new private clinic.
Then came the data cleaning process, partly automated, partly manual.
Technologies: PHP, MySQL, HTML, JavaScript, Mainframe, file system, refactoring.
My contribution: Implementation, migration.

Jan 2005 - Dec 2005

1 year

Development of a 3-layer application for an optics workshop

Project includes: data modeling, implementation of stored procedures in a SQL database, development of the user interface, development of the application server, development of the transfer protocol.
Technologies: OOD/OOP, Delphi, Pascal, Firebird, SQL, HTTP, TCP/IP, 3-layer.
Own contribution: Implementation.

Jan 2005 - Dec 2005

1 year

Development of a mail tool for an existing web framework on IIS

The tool saves incoming emails from the framework in its own database (Interbase), sends them in email actions, logs the events, creates reports on email actions (successfully completed, aborted), and finds repeated emails.
Then development of an admin panel in PHP4 (gaining first experience with web scripting languages like PHP).
Technologies: OOD/OOP, Delphi, Pascal, Interbase, SQL, HTTP, PHP.
Own contribution: Implementation.

Jan 2005 - Dec 2005

1 year

Development of a module in a database application for a city courier company

Managing incoming orders from customers, placing orders – connecting with available couriers.
Technologies: Delphi, Pascal, TCP/IP.
Own contribution: Implementation.

Jan 2005 - Dec 2005

1 year

Software package for TCP/IP transmission

A software package for TCP/IP transmission (as Delphi components) consisting of a multithreaded server and a client.
The server provides the following services: receiving binary data streams, storing data, logging events (client login/logout, data sent, data received, etc.).
Technologies: Delphi, Pascal, TCP/IP, multithreaded architecture, 3-layer.
Own contribution: Architecture, implementation.

Jan 1998 - Dec 2008

11 years

Complex system for general practitioners

Scheduling visits, managing the patient database, the digital patient record, diagnoses, medications, creating all necessary documents, reports for health insurance companies.
Development of an innovative editor for the digital patient record according to the WONCA ICPC principle.
The system was developed during this period and installed, introduced, and maintained in several medical practices.
Technologies: OOD/OOP, Delphi, Interbase/Firebird, Pascal, SQL.
Own contribution: Concept, architecture, implementation, testing, maintenance, sales.

Jan 1997 - Dec 2004

8 years

Object-oriented database for managing graphical and multimedia data in hospitals

Interfaces to all common image and video formats (JPG, DICOM, others) and medical measuring devices.
Parser for HL7 files (version 2.x).
Modeling of workflow processes.
Search engine.
Dynamic generation of input forms using a custom scripting language.
Report generator.
Technologies: OOD/OOP, Delphi, Interbase, Pascal, SQL, HL7, DICOM.
Own contribution: architecture, implementation, tests.

Jan 1997 - Dec 1998

2 years

Backend part for an online shop

Control of all processes, from receiving a customer order to complete inventory management, supplier orders, FIFO concept, generating documents like stock lists, invoices, shipping labels for carriers, delivery notes, etc.
Technologies: Delphi, Interbase, Pascal, SQL, stored procedures, triggers.
Own contribution: implementation.

Jan 1996 - Dec 1996

1 year

Szczecin, Poland

IT Manager

Tandem GmbH

Responsible for introducing and maintaining a complex solution for the leasing services sector.
Technologies: BackOffice Server, Interbase, Crystal Reports, LEO.
Own contribution: introduction, training, maintenance, configuration.

Jan 1995 - Dec 1997

3 years

Szczecin, Poland

IT coordinator

Car dealership

Organization of an inventory management system (introducing an external product) and a system for managing new car sales (own project).
Technologies: Delphi, Pascal, SQL, Windows, MS Access.
Own contribution: project management, implementation.

Jan 1992 - Dec 1995

4 years

Dortmund, Germany

Developer

Quantum

Creation of tool modules (in C) for inventory management systems.
Mainly a report generator using an interpretable BASIC-like language to generate report sheets in the existing inventory management system and a Management Information System.
Technologies: C, C++, lex/yacc, regular expressions, SQL, Unix.
Own contribution: implementation, tests.

Jan 1990 - Dec 1992

3 years

Berlin, Germany

Software developer

Mikrodata

Responsible for developing transfer software for the I80286 processor and frontend software for building control systems.
Technologies: Assembler, Pascal.
Personal contribution: implementation.

Jan 1988 - Dec 1990

3 years