Radek is available for hire

Radek Wiewior

Verified Expert in Engineering

Database Developer

Location

Jakarta, Indonesia

Toptal Member Since

July 6, 2022

Radek has 25 years in technology, looking for challanges unpossible to solve by others. Enterprise-class databases are his native environment. He has many years in Oracle Corporation using Oracle technologies. His favorites are performance tuning, system architecture, HA, and real-time replication, as well as the creation of Oracle experts in his free time. IT security is his second specialization.

Portfolio

Magnetar For Technology and Digital Solution Company PSC

Data Engineering, PostgreSQL, MongoDB, Oracle Cloud, MySQL, Performance Tuning...

Tokenomy Technologies

PostgreSQL, MySQL, Performance Tuning, Data Warehouse Design, SQL, JSON...

Goldenore

Oracle, SQL, Oracle Database Tuning, Data Reporting, Data Engineering, ETL...

Experience

Oracle - 20 years SQL - 20 years Java - 20 years Oracle Database Tuning - 20 years PL/SQL - 20 years Data Warehouse Design - 10 years

Availability

Part-time

Preferred Environment

Oracle, Data Engineering, Data Analysis, Data Analytics, Data Architecture, Databases, SQL DML, Performance Tuning, Data Queries, SQL Performance, Database Administration (DBA), Oracle PL/SQL, Stored Procedure, SQL Stored Procedures, Business Continuity & Disaster Recovery (BCDR), Oracle SQL, Oracle DBA, Database Architecture, Database Design

The most amazing...

...analysis I've done is a source code (seven million lines) and central database of the State Social Security's main system to replace with modern technologies.

Work Experience

Data Engineer

2022 - 2022

Magnetar For Technology and Digital Solution Company PSC

Designed and developed the engine of the data warehouse/ reporting subsystem.
Installed, configured, and deployed both UAT and PROD environments.
Tuned performance of around 50 million rows of tables extraction from Oracle data source. Reduced time from around 10 hours to around 2 minutes.

Technologies: Data Engineering, PostgreSQL, MongoDB, Oracle Cloud, MySQL, Performance Tuning, Red Hat Linux, Linux, Bash, Reporting, Data Transformation, Oracle DBA, Database Architecture, Database Design

Data Management Consultant

2021 - 2022

Tokenomy Technologies

Designed and created data warehouse reporting in nearly real-time from eight systems.
Created development procedures to make it possible and easy for future data warehouse development.
Tuned performance of ETL processes created by other developers and me. The time decreased was quite spectacular.

Technologies: PostgreSQL, MySQL, Performance Tuning, Data Warehouse Design, SQL, JSON, Data Reporting, Data Engineering, ETL, Data Warehousing, Data Analysis, Data Visualization, Data Analytics, Python, Data Architecture, API Integration, Microsoft Power BI, Databases, APIs, Integration, Microsoft Excel, SQL DML, Data Queries, SQL Performance, Database Administration (DBA), GitHub, Data Modeling, Data Pipelines, Business Intelligence (BI), Pipelines, Stored Procedure, SQL Stored Procedures, Data-level Security, Linux, Bash, Business Continuity & Disaster Recovery (BCDR), Finance, Reporting, Data Transformation, Database Architecture, Database Design, Web Scraping

Chief Technology Officer

2018 - 2020

Goldenore

Provided training to Oracle engineers to masterschip their skills.
Created architecture and supervised development projects, like creating a custom tool for performance tuning and monitoring for database and aplication server layers of system.
Took responsibility if things went wrong for the most complicated parts of projects.

Technologies: Oracle, SQL, Oracle Database Tuning, Data Reporting, Data Engineering, ETL, Data Warehousing, Data Analysis, Data Visualization, Data Analytics, Python, Data Architecture, API Integration, Databases, APIs, Integration, Microsoft Excel, SQL DML, Performance Tuning, Data Queries, SQL Performance, Database Administration (DBA), GitHub, Oracle PL/SQL, Data Modeling, Data Pipelines, Migration, Oracle Cloud, Business Intelligence (BI), Pipelines, Stored Procedure, SQL Stored Procedures, Data-level Security, Linux, Bash, PL/SQL, Business Continuity & Disaster Recovery (BCDR), Oracle SQL, Data Migration, Finance, Reporting, Data Transformation, Oracle DBA, Database Architecture, Database Design

Database Architect

2016 - 2018

Proximus

Migrated data from the source system, Oracle JD Edwards, to SAP. Lots of work in tuning performance.
Designed the architecture of the Central Repository of Network Assets, GIS system.
Managed data migration from six source systems to the Central Repository of Network Assets. Used six different GIS technologies.

Technologies: Oracle, SAP, Data Migration, GIS, IT Systems Architecture, SQL, Oracle Database Tuning, Data Reporting, Data Engineering, Data Analysis, Data Visualization, Data Analytics, Python, Data Architecture, API Integration, Databases, APIs, Integration, Microsoft Excel, SQL DML, Performance Tuning, Data Queries, SQL Performance, Database Administration (DBA), GitHub, Oracle PL/SQL, Data Modeling, Data Pipelines, Migration, Oracle Cloud, Pipelines, Stored Procedure, SQL Stored Procedures, Linux, Bash, PL/SQL, Business Continuity & Disaster Recovery (BCDR), Oracle SQL, Reporting, Data Transformation, Oracle DBA, Database Architecture, Database Design

Databases Expert and Auditor

2016 - 2016

Trusted Information Consulting Sp. z o.o

Audited central government systems, including the database layer area. Managed the design, high availability (HA), and security verification.
Managed a state social security (ZUS) system modernization possibilities analysis. ZUS KSI is the largest IT system in this part of Europe. At that time, maintenance was possessed by a single specific IT company. The target was to demonopolize.
Led a POC and analysis of over seven million lines of source code, port DB2 database of tousands of tables to new enviroment. Prove was provided that migration to a new modern technological stack is possible and not so expensive.

Technologies: IT Systems Architecture, IT Security, SQL, Data Engineering, Data Analysis, Data Analytics, Python, Data Architecture, Databases, Integration, Microsoft Excel, SQL DML, Data Queries, T-SQL (Transact-SQL), Database Administration (DBA), Oracle ERP, Oracle PL/SQL, Data Modeling, Data Pipelines, Pipelines, Stored Procedure, SQL Stored Procedures, Data-level Security, Linux, Bash, PL/SQL, Business Continuity & Disaster Recovery (BCDR), Oracle SQL, Reporting, Oracle DBA, Database Architecture, Database Design

Head Technical Consultant | Owner

2006 - 2016

Royal Software

Created a team of Oracle Experts from scratch. Some of them are now Oracle Certified Masters and Oracle ACE recipients.
Provided reasonable-priced Oracle-based solutions to customers.
Built custom Oracle EBS module from scratch to manage investment and integrate it with existing EBS installation.
Developed a Gis-class system. A central bank of geodetic networks for a government customer.
Managed the development of A.PL internet supermarket in Oracle iStore.
Maintained GEOPORTAL.GOV.PL, including a high service-level agreement (SLA).
Provided subcontractor services to Oracle Consulting for many customers.

Technologies: Oracle, SQL, Oracle Database Tuning, Data Reporting, Data Engineering, ETL, Data Warehousing, Data Analysis, Data Visualization, Data Analytics, Data Architecture, API Integration, Databases, APIs, Integration, Microsoft Excel, SQL DML, Performance Tuning, Data Queries, SQL Performance, T-SQL (Transact-SQL), Database Administration (DBA), GitHub, Oracle Application Express (APEX), Apex, Oracle ERP, Oracle PL/SQL, Batch Apex, SugarCRM, Data Modeling, Data Pipelines, Migration, Business Intelligence (BI), Pipelines, Stored Procedure, SQL Stored Procedures, XML for Analysis (XMLA), Data-level Security, Linux, Bash, PL/SQL, Business Continuity & Disaster Recovery (BCDR), Oracle SQL, Data Migration, Finance, Reporting, Data Transformation, CRM APIs, Oracle DBA, Crystal Reports, Database Architecture, Database Design

Senior Instructor

2002 - 2006

Oracle

Provided Oracle-certified training to Oracle professionals.
Revised the programming path, including SQL, PL/SQL, Java, Jakarta EE, Oracle Forms, and reports.
Reviewed the administration path, including administration, backup and recovery, and network.
Checked the HA path, including data guard and RAC; the. options path, partitioning and spatial; and the performance tuning path, including SQL, PL/SQL, and database.
Led internal training for Oracle's employee support. Performed a detailed disaster analysis, including an analysis of Oracle's database source code.

Technologies: Oracle, SQL, Oracle Database Tuning, Data Reporting, Data Engineering, ETL, Data Warehousing, Data Analysis, Data Visualization, Data Analytics, Data Architecture, Databases, APIs, Integration, Microsoft Excel, SQL DML, Performance Tuning, Data Queries, SQL Performance, Database Administration (DBA), Oracle Application Express (APEX), Apex, Oracle ERP, Oracle PL/SQL, Batch Apex, Data Modeling, Data Pipelines, Migration, Business Intelligence (BI), Pipelines, Stored Procedure, SQL Stored Procedures, Data-level Security, Linux, Bash, PL/SQL, Business Continuity & Disaster Recovery (BCDR), Oracle SQL, Data Migration, Finance, Reporting, Data Transformation, Oracle DBA, Database Architecture, Database Design

Software Engineer

1999 - 2002

Oracle

Performed as a contractor in Oracle Consulting, delivering technical solutions.
Developed a solution to allow authentication for the National Police Information System via the Radius server.
Provided financial reports, Oracle reports, and PL/SQL for Hortex.
Solved bugs in Oracle EBS inter-module data transformation.
Managed dozens of other projects based on Oracle technologies.

Technologies: Oracle, SQL, Oracle Database Tuning, Data Reporting, Data Engineering, Data Analysis, Data Visualization, Data Analytics, Data Architecture, API Integration, Databases, APIs, Integration, Microsoft Excel, SQL DML, Performance Tuning, Data Queries, SQL Performance, Oracle Application Express (APEX), Apex, Oracle ERP, Oracle PL/SQL, Batch Apex, Data Modeling, Data Pipelines, Migration, Business Intelligence (BI), Pipelines, Stored Procedure, SQL Stored Procedures, Data-level Security, Linux, Bash, PL/SQL, Business Continuity & Disaster Recovery (BCDR), Oracle SQL, Finance, Reporting, Data Transformation, Oracle DBA, Database Architecture, Database Design, Excel VBA

Microsoft Certified Trainer

1995 - 1999

C.S. Edusoft

Trained on Windows NT Server advanced administration, including security.
Taught SQL Server administration and Transact-SQL development.
Gave training on Visual Basic, Visual C++, Visual Fox Pro, and other development tools.

Technologies: Windows NT Server, Microsoft SQL Server, Microsoft Visual Studio, SQL, Data Engineering, ETL, Data Warehousing, Data Analysis, Data Visualization, Data Analytics, Data Architecture, Databases, Microsoft Excel, SQL DML, Performance Tuning, Data Queries, SQL Performance, T-SQL (Transact-SQL), Database Administration (DBA), .NET, Data Modeling, Stored Procedure, SQL Stored Procedures, Data-level Security, Business Continuity & Disaster Recovery (BCDR), Finance, Reporting, Microsoft DBA, Crystal Reports, Database Architecture, Database Design, Excel VBA

Software Engineer

1994 - 1995

Quality Business Software (QBS)

Created reports for existing systems in customers environment.
Designed and implemented a system to manage doctors' offices.
Created and customized the end user interface in existing systems.

Technologies: Object Pascal, Microsoft Access, dBASE, Visual FoxPro, SQL, Data Reporting, Data Engineering, Data Analysis, Data Analytics, Databases, Microsoft Excel, SQL DML, Data Queries, .NET, Data Modeling, Reporting, Database Architecture, Database Design

Experience

Tokenomy Singapore

I designed a technical project and implemented a new data warehouse based on eight transactional production systems.

The project is now fully operational and used by customers in production. Because of high time requirements, I did lots of performance tuning work.

Migration of Production Warehouse from Oracle Exadata 4 to Oracle Exadata 6 with Realtime

http://www.pocztowy.pl/

I designed and performed the migration process of the Pocztowy Bank's production warehouse.

Migrated from Oracle Exadata 4 to Oracle Exadata 6 and worked on tuning performance. The requirement from the customer was a service window of about 10 minutes.

Polish Gas Company (PS Gaz)

http://www.psgaz.pl/en

I designed the architecture and supervised the implementation of the ETL system to supply the Central Repository of Network Assets from five source systems, including GIS type with different formats for storing spatial data.

Polish Gas Company (PS Gaz) | Migraton of Source Systems to SAP

http://www.psgaz.pl/en

Migrated a multi-million record set from many source systems and supplied them with the SAP system.

Competences used
Oracle, SQL, PL / SQL, BI, ETL, performance tuning, pre-tuning forecast of around 50,000 years, a post-tuning execution time of fewer than 0.1 seconds, and other multiple aggregations of tables with an approximation of around 1 million records.

Polskie Wody (KZGW) | IT System of The Country Shield (ISOK)

Managed the audit and redesign of the architecture and supervised the implementation of the ISOK system.

I also created a logical and physical data model for the ISOK system based on Oracle Database.

Audit of Systems | Central Register of Vehicles and Drivers, and System of State Registers

I performed audits of systems in the areas of Oracle and DB2 database design. Managed high availability and security issues on the databases layer.

• www.cepik.gov.pl
• www.gov.pl/web/cyfryzacja/system-rejestrow-panstwowych

State Social Security (ZUS)

http://www.zus.pl/slownik/-/letter/K/kompleksowy-system-informatyczny-ksi-zus-/21738

I conducted the architectural team that created the baseline and documentation to implement the Corporate Service bus.

Analyzed the source code of over seven million lines and the central database of ZUS's primary system (KSI) to analyze the possibility and create a scenario of replacing KSI with modern technologies.

Role
Deputy head of the architectural team

NC and Canal+ Poland

https://pl.canalplus.com/

I delivered maintenance support in over 200 instances in Oracle databases.

Trained new DBAs on specific, one-of-a-kind sets of maintenance procedures for databases of the clients' production systems.

I guaranteed architectural support in preparing and launching backup and recovery and preparing about 200 UAT environments. Prepared and performed data anonymization procedures for development and test environments.

Delivered support in performance tuning of Oracle databases.

Polish Post

http://www.poczta-polska.pl/

I created a team of administrators to maintain customers' Oracle databases with high SLA requirements.

Role
Maintenance team manager

Competences used
Maintenance of Oracle databases and Oracle Exadata, Zabbix

KGHM Poland

https://kghm.com/

I managed the audits of the Central Purchasing System (SWZ) in the areas of security.

Analyzed thousands of source codes, Jakarta EE, and structure and contents of the central database. I also created a tool to import and perform a brief analysis of HTTP and HTTPS requests access logs to allow the IT department to verify user-discovered vunerabilitys.

Ceramika Nowa Gala

https://nowa-gala.com.pl/

I created a new custom module from scratch for Oracle EBS, handling investments, integration, implementation, and production launch.

Managed the architectural design of a new module, provided training on Oracle EBE internal specifics for the developers' team, and supervised the module's implementation.

Role
Chief of the developers' team and architect.

Police Headquarters | National Police Information System (KSiP)

https://policja.pl/

Managed the development of a solution allowing authentication for the National Police Information System via Radius server.

Role
Software engineer - Oracle Consulting contractor

Competences Used
C, C++, Oracle Pro C, security.

A.PL (Action Group)

http://a.pl

Worked on the development, production run, and maintenance of one of the first internet galleries in Poland. I trained and supervised a team of developers, system/database administrators, and the project. This was the first implementation in this part of Europe of Oracle iStore (2007-2008).

Skills

Languages

SQL, SQL DML, Stored Procedure, Java, Python, T-SQL (Transact-SQL), Bash, Excel VBA, C++, C, Object Pascal, dBASE, Visual FoxPro, Apex

Paradigms

Database Design, ETL, Business Intelligence (BI), OLAP

Platforms

Oracle, Oracle Database, Linux, Microsoft, Jakarta EE, Red Hat Linux

Storage

PostgreSQL, PL/SQL, Oracle Database Tuning, Databases, SQL Performance, Database Administration (DBA), Oracle PL/SQL, SQL Stored Procedures, Oracle SQL, Oracle DBA, Microsoft DBA, Database Architecture, Microsoft SQL Server, Data Pipelines, Oracle Cloud, MySQL, MariaDB, JSON, IBM Db2, MongoDB

Other

Performance Tuning, Data Migration, Data Engineering, Data Analysis, Data Analytics, Data Architecture, API Integration, APIs, Integration, Data Queries, Data Modeling, Migration, Data-level Security, Business Continuity & Disaster Recovery (BCDR), Reporting, Data Transformation, Data Warehouse Design, IT Security, Data Reporting, Data Warehousing, Data Visualization, Pipelines, XML for Analysis (XMLA), Finance, CRM APIs, Web Scraping, Oracle Performance Tuning, System Architecture Design, Oracle Spatial, PL/SQL Tuning, SAP, IT Systems Architecture, Business Analysis, System Design, Sparx Enterprise Architecture, Reverse Engineering, Risk Analysis, Digital Forensics, Oracle EBS, Windows NT Server, System Administration, Administration

Frameworks

.NET

Tools

Microsoft Access, Microsoft Excel, GitHub, Oracle ERP, Microsoft Power BI, Oracle Exadata, GIS, Oracle Tuxedo, Zabbix, Oracle Forms, Oracle Reports, Microsoft Visual Studio, Oracle Application Express (APEX), Batch Apex, SugarCRM, Crystal Reports

Libraries/APIs

Zendesk API

Education

1991 - 1997

Master's Degree in Computer Science Engineering

Warsaw University of Technology - Warsaw, Poland

Certifications

AUGUST 2002 - PRESENT

Oracle Certified Professional (OCP)

Oracle

MAY 1998 - PRESENT

Microsoft Certified Database Administrator

Microsoft

MAY 1998 - PRESENT

Microsoft Certified System Engineer

Microsoft

OCTOBER 1997 - PRESENT

Microsoft Certified Trainer

Microsoft

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