Joanna Lewandowska

Junior Data Analyst Portfolio

I am developing my skills in data analysis and building portfolio projects based on Excel, SQL, Power BI and Python.

About me

I recently completed a Junior Data Analyst course where I worked with spreadsheets, SQL, Business Intelligence tools and Python. I am now using this knowledge to build practical projects and document my learning process.

My goal is to get my first role as a Junior Data Analyst, Reporting Analyst or Junior BI Analyst.

Skills

Excel

Formulas, Pivot Tables, filtering, charts, dashboards and data cleaning.

SQL

Queries, joins, aggregations, views, creating and modifying tables.

Power BI

Power Query, data models, DAX, KPI dashboards and interactive reports.

Microsoft 365 / Business Applications

Microsoft Lists, SharePoint Lists, CRM-lite system design, JSON column formatting, Power Automate specifications and business process documentation.

Python

Pandas, data cleaning, exploratory data analysis and basic visualizations.

Statistics

Basic statistical analysis, hypothesis testing and interpreting results.

Business Intelligence

Dashboard design, Looker Studio reports and presenting data insights clearly.

Portfolio projects

Excel Sales Dashboard

An interactive sales dashboard created in Excel using Power Query, Pivot Tables, Pivot Charts and slicers. The project analyzes sales, profit, regions, product categories, discounts, shipping methods and top-selling products.

Status: completed

View project on GitHub

SQL E-commerce Analysis

SQL analysis of Brazilian e-commerce data from Olist. The project explores sales performance, customer behavior, product categories, seller performance, payment methods, delivery delays and customer review scores.

Status: completed

View project on GitHub

Power BI Sales Performance Dashboard

An interactive sales performance dashboard built in Power BI using the Financial Sample dataset. The dashboard analyzes sales, profit, profit margin, units sold, countries, customer segments and product performance.

Status: completed

View project on GitHub

SharePoint Client Management System

CRM-lite client management system designed with Microsoft Lists, SharePoint Lists and Power Automate specifications. The project includes structured client data, related contacts, interaction history, opportunities, follow-up tasks, filtered views, JSON column formatting and automation-ready documentation.

Status: completed

View project on GitHub

Looker Studio Marketing Dashboard

A simple marketing dashboard focused on traffic, clicks, conversions and campaign performance.

Status: planned / in progress

Python Sales Analysis

An exploratory data analysis project using Python, Pandas and visualizations.

Status: planned / in progress

Python Customer Segmentation

A customer segmentation project based on purchasing behavior, RFM analysis and clustering.

Status: planned / in progress

What I am working on now

I am currently preparing my first portfolio projects and learning how to present analysis results in a clear and practical way.

Contact

Email: joannalewandowska025@gmail.com

GitHub: joannlewandowska

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