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I am a data professional with 4 years of experience working with large-scale datasets to extract actionable insights that drive business decision-making. My expertise spans Python (pandas, NumPy, SciPy, scikit-learn), SQL, R, and Excel, with a focus on statistical analysis, machine learning model optimisation, and automating data workflows. I have a strong background in building robust ETL pipelines, managing financial transaction data, and producing clear, impactful reports and visualisations for senior management. I’m passionate about leveraging data to improve efficiency, streamline processes, and deliver strategic value.…I am a data professional with 4 years of experience working with large-scale datasets to extract actionable insights that drive business decision-making. My expertise spans Python (pandas, NumPy, SciPy, scikit-learn), SQL, R, and Excel, with a focus on statistical analysis, machine learning model optimisation, and automating data workflows. I have a strong background in building robust ETL pipelines, managing financial transaction data, and producing clear, impactful reports and visualisations for senior management. I’m passionate about leveraging data to improve efficiency, streamline processes, and deliver strategic value.

Jakub Mieldzicz

Data Analyst, Data Scientist, Data Visualizer

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I am a data professional with 4 years of experience working with large-scale datasets to extract actionable insights that drive business decision-making. My expertise spans Python (pandas, NumPy, SciPy, scikit-learn), SQL, R, and Excel, with a focus on statistical analysis, machine learning model optimisation, and automating data workflows. I have a strong background in building robust ETL pipelines, managing financial transaction data, and producing clear, impactful reports and visualisations for senior management. I’m passionate about leveraging data to improve efficiency, streamline processes, and deliver strategic value.…I am a data professional with 4 years of experience working with large-scale datasets to extract actionable insights that drive business decision-making. My expertise spans Python (pandas, NumPy, SciPy, scikit-learn), SQL, R, and Excel, with a focus on statistical analysis, machine learning model optimisation, and automating data workflows. I have a strong background in building robust ETL pipelines, managing financial transaction data, and producing clear, impactful reports and visualisations for senior management. I’m passionate about leveraging data to improve efficiency, streamline processes, and deliver strategic value.

Available to hire

I am a data professional with 4 years of experience working with large-scale datasets to extract actionable insights that drive business decision-making. My expertise spans Python (pandas, NumPy, SciPy, scikit-learn), SQL, R, and Excel, with a focus on statistical analysis, machine learning model optimisation, and automating data workflows. I have a strong background in building robust ETL pipelines, managing financial transaction data, and producing clear, impactful reports and visualisations for senior management. I’m passionate about leveraging data to improve efficiency, streamline processes, and deliver strategic value.

Skills

Experience Level

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Expert

Intermediate

Language

English

Fluent

Polish

Fluent

Work Experience

Data Analyst at Byborg IP S.à r.l.

August 1, 2025 - August 1, 2025

Analysed large-scale video-streaming data (100M+ rows) to uncover behavioural trends and correlations between user engagement actions, supporting product and content strategy decisions. Delivered concise, data-driven reports and visualisations to senior management fortnightly, translating complex analyses into clear, actionable insights for business and product teams. Optimised machine learning recommender models, improving recommendation accuracy by 2-3% through parameter tuning and validation on large user-session datasets. Refactored Python data pipelines (pandas, NumPy, SciPy) to improve performance and scalability, reducing data processing time from several hours to under a minute. Monitored and validated data quality both offline and live through Kibana dashboards, ensuring correct event capture and identifying inconsistencies across key engagement metrics. Collaborated in an Agile Scrum environment, contributing to sprint planning, daily stand-ups, and iterative delivery of anal

Finance Analyst at Thomas Miller

May 1, 2025 - May 1, 2025

Automated key financial processes using R and SQL, reducing month-end close time from several days to a few hours and improving reporting accuracy and efficiency. Developed and maintained a custom R library to standardise and automate reporting workflows, covering variance analysis, account reconciliations, audit preparation, and data validation. Built and maintained a robust ETL pipeline for financial transaction data, ensuring reliable data flow between source systems and the accounting general ledger, and improving data consistency across reports. Converted complex regulatory requirements and business logic into robust data models and automated reports, ensuring compliance and producing accurate, audit-ready outputs. Prepared detailed financial analyses and visual reports presented monthly at finance committee meetings, providing insights that informed senior management decisions and strategic planning. Collaborated with the actuarial team to enhance and maintain shared R packages,