Open to opportunities

Bartosz Kowalski

@bartoszkowalski

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Database-focused analyst and backend developer building ETL pipelines, reliable reporting, and BI-ready Excel outputs.

Poland

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What I'm looking for

I’m looking for a role where I can own the full data flow—ETL, reliable SQL/PL-SQL, and automated reporting—while building practical internal tools. I value data quality, clear ownership, and teams that support continuous improvement.

I’m a database-focused analyst and backend developer with commercial experience across Oracle, PostgreSQL, MSSQL, and Teradata, pairing strong Python with SQL/PL-SQL to build end-to-end data flows. I enjoy owning everything from raw extraction and transformation logic to automated, Excel/BI-ready outputs.

In my current role as a Database Analyst / Backend Developer at Getin Noble Bank, I develop and optimize PL/SQL (Oracle) for loan and repayment-schedule reporting—using CTEs and window functions for accurate annuity, interest, and balance calculations. I’ve also automated recurring reporting with Python + SQL exports and Task Scheduler, and built a Django reporting application that syncs data from Oracle into PostgreSQL.

Previously at Polkomtel, I designed and optimized ETL pipelines between Teradata and MSSQL, automated recurring workflows, and improved productivity and response times through JavaScript automation and Power Apps/Power Automate solutions. Across earlier database and implementation work, I’ve optimized slow SQL to dramatic time savings, stabilized production jobs, and built internal tools and dashboards so teams can act on trustworthy data.

Experience

Work history, roles, and key accomplishments

Current

Database Analyst / Backend Developer

Current

Getin Noble Bank

Jan 2026 - Present (5 months)

Developed and optimized PL/SQL (Oracle) queries for loan and repayment-schedule reporting using multi-level CTEs and window functions. Automated recurring Excel exports with Python and Task Scheduler, maintained a Django reporting app syncing Oracle to PostgreSQL, and fixed a production Excel export bug caused by HTTP streamed responses.

Oracle PL SQL SQL Query Optimization Window Functions Pandas Django PostgreSQL HTTP Streaming Debugging

Frontend Developer

Gamify

Nov 2025 - May 2026 (6 months)

Developed user-facing pages and components for a bioinformatics learning platform using React.js and TypeScript within two-week Scrum sprints. Implemented reusable UI components and performance optimizations to improve navigation smoothness.

React TypeScript UI Components Performance Optimization Agile Scrum UI Development

Senior Data Integration Specjalist

Polkomtel Sp. Z O.o.

Aug 2024 - Jan 2026 (1 year 5 months)

Designed and optimized ETL pipelines between Teradata and MSSQL to deliver accurate, timely data across departments. Automated SMS handling with JavaScript (25% less manual workload, 40% faster responses), built Power Apps/Power Automate workflows (10 hours/week saved; 30% faster processing), and improved internal tool usability with lightweight React apps for 100+ employees.

Teradata MSSQL Power Automate React Technical Documentation

Database Specialist

Netia S.A.

Jun 2023 - Aug 2024 (1 year 2 months)

Developed complex PL/SQL scripts and optimized SQL code, reducing report generation time from 2 hours to 20 minutes. Monitored and improved recurring database jobs to increase reliability while overseeing consistent, secure data exchange and supporting customer communication campaigns for 50,000+ clients.

Pl SQL SQL Query Optimization Scheduled Jobs Database Reliability Data Exchanges Reporting Systems Email SMS Campaign Data

EAM/CMMS Implementation Consultant

SimplyMobile

Nov 2021 - Jun 2023 (1 year 7 months)

Configured and customized EAM/CMMS systems for corporate clients, improving asset-tracking efficiency by 15%. Extended system functionality with T-SQL triggers, procedures, and functions, implemented automated email/push/SMS notifications, and managed Microsoft IIS deployments using Azure DevOps release processes.

T SQL Procédures Functions Database Integration Automated Notifications (Email Push SMS)Microsoft IIS Azure DevOps System Customization