Sebastian Więckowski, Developer in Warsaw, Poland
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Sebastian Więckowski

Verified Expert  in Engineering

Business Analyst and Software Developer

Warsaw, Poland

Toptal member since November 5, 2021

Expertise
Data WarehouseData AnalysisData ScienceSQLOracle DevelopmentExcel DevelopmentUMLETLDatabaseSAS
Bio

Sebastian is an experienced business analyst and developer in the data warehouse and integration area. He has a background in financial instruments, banking, and telecom sectors. Sebastian held technical analyst, developer, business analyst, and IT project management positions during his career.

Portfolio

Payback
SAS, SAS SQL, Base SAS, Oracle, Oracle PL/SQL, SQL, Jenkins, Subversion (SVN)...
SimCorp
Investment Banking, Financial Data, Finance, Financial Institutions, Securities...
Deutsche Bank
Oracle, Workflow, UML, Visio, IT Business Analysis, Systems Analysis...

Experience

  • SQL - 15 years
  • Oracle - 12 years
  • IT Business Analysis - 11 years
  • Reporting - 10 years
  • Financial Data - 9 years
  • Systems Analysis - 7 years
  • SQL Performance - 6 years
  • PL/SQL - 5 years

Availability

Part-time

Preferred Environment

Windows, Oracle, SAS, Enterprise Architecture, SimCorp, Toad, Visio

The most amazing...

...was data mart I've designed and developed covered the whole reporting for the biggest telecom company in Poland in warehouse management, wholesale, and retail.

Work Experience

SAS and Oracle Developer

2022 - PRESENT
Payback
  • Improved the existing processes by implementing a tool to run failed or not started SAS jobs automatically.
  • Tracked and fixed bugs using Jira as a reporting tool during an OPS shift in the DevOps environment.
  • Contributed to smaller and bigger improvements in the existing processes by introducing changes in the SAS macros, SQL, and PL/SQL scripts.
Technologies: SAS, SAS SQL, Base SAS, Oracle, Oracle PL/SQL, SQL, Jenkins, Subversion (SVN), Confluence, Jira, SQL DML, SQL DDL, Testing, Unit Testing, Stored Procedure, SQL Stored Procedures

Business Consultant

2017 - 2022
SimCorp
  • Built integration for two central banks between SimCorp Dimension and their internal systems and external counterparties. Worked from clarification and design phase, implementation, and support during UAT.
  • Enhanced, maintained, and customized the interface to IHS Markit for OTC instruments confirmation for client's needs. The interface allows the OTC trade confirmation process to be fully automated.
  • Implemented interfaces during SimCorp Dimension implementation projects using SimCorp's communication server, filter toolbox, data extractor, and data import.
  • Built an interface to import financial positions managed by external managers into SimCorp Dimension for a reserve fund led by a European government. The interface transformed and imported data from various sources.
Technologies: Investment Banking, Financial Data, Finance, Financial Institutions, Securities, Derivatives, XML, XSLT, SQL, Message Queues, Oracle, APIs, ETL, Crystal Reports, Integration, Data Integration, Dashboards, Data-driven Dashboards, REST APIs, Office 365

Business Analyst | IT Project Manager

2012 - 2017
Deutsche Bank
  • Served as a business analyst and IT project manager for the loan application supporting system project. I was accountable for the project budget, plan, and schedule, reporting the steering committee's project and financial status.
  • Acted as a business analyst during the wealth management system implementation that consolidates all client's investments view and supports investment advisors' decisions about the client's portfolio.
  • Analyzed business requirements and designed changes in the data warehouse and the data marts. Supported business units during UAT.
  • Worked as a business analyst and IT project manager during the implementation of a commission and incentive system.
Technologies: Oracle, Workflow, UML, Visio, IT Business Analysis, Systems Analysis, IT Project Management, Data Warehousing, Data Warehouse Design, Business Intelligence (BI), SQL, ETL, Databases, Data Marts, Kimball Methodology, Microsoft Excel, Microsoft Access, Excel 2010, Excel 2013, Excel 2007, Architecture, Data Architecture

Data Warehouse Engeneer

2009 - 2011
StatConsulting (Project for Plus)
  • Developed and maintained the analysis platform containing data marts and reports.
  • Supported business users by gathering and analyzing requirements, designing and developing reports in Teradata or SAS.
  • Developed and maintained reports for the controlling department and top management.
Technologies: SAS, SQL, Teradata SQL Assistant, Teradata Databases, SAS Enterprise Guide, Data Warehousing, Data Warehouse Design, Business Intelligence (BI), Databases, Data Analytics, Data Analysis, Database Management, Excel 2010, Microsoft Access, Microsoft Excel

Senior ERP System Analyst

2007 - 2009
Orange
  • Built an integration layer in Oracle PL/SQL between the ERP and warehouse management systems.
  • Supported business users by gathering and analyzing requirements, designing changes, and working with the system vendor to implement changes.
  • Performed unit and integration testing changes delivered by the system vendor and supported business users during the UAT phase.
Technologies: SQL, PL/SQL, Industrial and Financial Systems (IFS), UML, Enterprise Architecture, Databases, Database Schema Design, Oracle, SQL DML, SQL DDL, Windows, Toad, SQL Performance, APIs, Database Design, Integration, Business Analysis, IT Business Analysis, Testing, REST APIs, Stored Procedure, SQL Stored Procedures

Data Warehouse Engineer

2005 - 2006
Orange
  • Designed and developed a data mart covering the whole reporting for the biggest telecom company in Poland in areas like warehouse management, wholesale, and retail sales.
  • Built many SQL and PL/SQL-based reports for various business areas like marketing, finance, warehouse management, and billing.
  • Tuned many existing cyclical SQL reports, significantly improving their performance.
Technologies: Oracle, SQL, PL/SQL, SQL Performance, Data Warehouse Design, Data Warehousing, Business Intelligence (BI), Databases, Database Architecture, Data Analytics, Data Analysis, Database Schema Design, Database Management, Database Management Systems (DBMS), SQL DML, SQL DDL, Stored Procedure, SQL Stored Procedures

Experience

Central Bank Reserve Management System Integration

I implemented interfaces integrating the SimCorp Dimension system for two central banks. I integrated SimCorp Dimension with the bank's internal systems as well counterparties systems. I was working from the clarification and design phase, implementation, and supporting users during UAT.

Data Marts and Reporting Project

I have designed and developed data marts covering the whole reporting for the biggest telecom company in Poland in warehouse management, wholesale, and retail. I worked as an analyst and developer on that project.

Regulatory Changes in The Mortgage Application System

I completed a project with regulatory changes in the mortgage application system, working as the IT project manager. The deadline to implement changes was very short, and we were able to meet it. Completing the project in time allowed the bank to continue selling mortgages

B2B Portal Project

I worked as a business and system analyst to implement B2B portal in Orange, Poland. A vendor delivered the system. My role was to analyze internal client-specific requirements and work with the vendor to implement them. I was also responsible for unit test the whole system and supporting business units during UAT.

Data Analyst

Acted as a data analyst to help the client to get a clear and up-to-date picture of business performance. I translated business problems into SQL queries, analyzed data, and composed, tested, and ran SQL queries against the Redshift database. I also documented all the work in reproducible steps, producing comprehensive reports to communicate results.

Education

2002 - 2008

Master's Degree in Computer Science

Warsaw University of Technology - Warsaw, Poland

Certifications

OCTOBER 2022 - PRESENT

Build a Back-end REST API with Python and Django

Udemy

OCTOBER 2022 - PRESENT

2022 Python for Machine Learning & Data Science Masterclass

Udemy

SEPTEMBER 2022 - PRESENT

Learn Python Programming Masterclass

Udemy

OCTOBER 2017 - PRESENT

SimCorp's Certified Connectivity Specialist

SimCorp

SEPTEMBER 2017 - PRESENT

Simcorp's Certified Reporting Specialist

SimCorp

SEPTEMBER 2017 - PRESENT

SimCorp Dimension Specialist

SimCorp

SEPTEMBER 2015 - PRESENT

Agile Project Management Foundation

APMG International

MAY 2014 - MAY 2019

PRINCE2 Practitioner

APMG International

JUNE 2013 - PRESENT

PRINCE2 Foundation

APMG International

SEPTEMBER 2012 - PRESENT

ITIL Foundation

EXIN

Skills

Libraries/APIs

REST APIs, Scikit-learn, NumPy, Pandas

Tools

Toad, Excel 2010, Microsoft Excel, Excel 2013, Excel 2007, Visio, MATLAB, Teradata SQL Assistant, SAS Enterprise Guide, Crystal Reports, Microsoft Access, Jenkins, Subversion (SVN), Confluence, Jira, Snowplow Analytics, IntelliJ IDEA

Languages

SQL, SQL DML, SQL DDL, SAS, UML, XML, XSLT, Stored Procedure, C++, Java, C, ABAP, Python 3, Python

Paradigms

Kimball Methodology, Business Intelligence (BI), Database Design, ETL, Testing, PRINCE2, Agile Project Management, ITIL, User Acceptance Testing (UAT), B2B, Unit Testing

Storage

SQL Performance, PL/SQL, Databases, SAS SQL, Oracle PL/SQL, SQL Stored Procedures, Teradata Databases, Microsoft SQL Server, Database Architecture, Data Integration, MySQL, Database Management, Database Management Systems (DBMS), Redshift

Platforms

Oracle, Windows, Jupyter Notebook

Frameworks

Django

Other

IT Business Analysis, Systems Analysis, Data Warehousing, Data Analytics, Data Analysis, Data Marts, Business Analysis, Database Schema Design, Enterprise Architecture, SimCorp, Financial Data, Financial Institutions, Securities, Derivatives, Reporting, Data Architecture, Data Warehouse Design, Excel Expert, Base SAS, Decision Support Systems, SAP, Industrial and Financial Systems (IFS), Workflow, IT Project Management, Investment Banking, Finance, Message Queues, APIs, Communications Server, Financial Market Data, Integration, Dashboards, Data-driven Dashboards, Vendor Management, Architecture, Office 365, Machine Learning, Supervised Machine Learning, Data Engineering, Exploratory Data Analysis, Database Analytics

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