Neslihan Oztas
Portfolio

Data Analyst skilled in SQL, Tableau, Power BI, Excel, Python, R @NeslihanTheAnalyst

Olist E-Commerce Analytics — Databricks | PySpark | Power BI

End-to-end analytics on Olist's 96K real Brazilian e-commerce orders (2016–2018). Built a Medallion data pipeline in Databricks using PySpark and SQL (Bronze → Silver → Silver Enriched → Gold), orchestrated as a Databricks Workflow DAG that runs the full pipeline in ~9 minutes. Modeled 5 Gold KPI tables and built a Power BI dashboard covering revenue, delivery performance, product categories, and customer retention. Key business insight: Olist grew 120% YoY to R$ 14M GMV, but 96% of customers buy only once — an acquisition engine without a retention strategy.

Bike Sales Performance Data Pipeline — Databricks | PySpark | Delta Lake

End-to-end data pipeline integrating CRM and ERP datasets into a unified analytics model. Built in Databricks using a Medallion architecture (Bronze → Silver → Gold) with PySpark transformations and Delta Lake. The Gold layer is structured as a star schema for reporting, supporting cross-functional KPI tracking across sales, customer, and product dimensions. Fully automated execution and version-controlled on GitHub.

NYC Motor Vehicle Collisions Analysis

A data-driven project using SQL for data cleaning, EDA for insights, and Power BI for dashboarding. This analysis explores traffic crashes across NYC to identify high-risk locations, top contributing factors, and vulnerable road users. Designed to inform safety initiatives by the NYC Department of Transportation.

Data Cleaning in SQL

This dataset provides information on tech industry layoffs from 2020-2022, including company names, industries, locations, and funding.

Customer Call List Cleaning (Python)

This project demonstrates how to clean a real-world customer call list dataset using pandas. The goal is to make the data usable for analysis by removing noise, fixing formatting issues, and eliminating duplicates or invalid entries.

Movie Correlation with Python

This project explores the relationships between a movie’s budget, gross earnings, and other features to identify which factors are most correlated with financial success.

Book Data Web Scraper with Python

This project demonstrates how to scrape book data from a website using BeautifulSoup and requests. The scraped data includes book titles, prices, and ratings, and is saved into a structured DataFrame for future analysis.

Penguin Classification Analysis with R

This project explores the Palmer Penguins dataset to investigate morphological differences across species and predict the sex of penguins using various statistical and machine learning techniques. It demonstrates an end-to-end data science workflow in RStudio— from data cleaning to statistical modeling and evaluation.

HR Analytics Dashboard - Attrition Insights in Power BI

Screenshot of HR Analytics Dashboard showing employee attrition insights by gender, salary, and job role. An interactive Power BI dashboard analyzing employee attrition trends. Highlights attrition patterns across departments, roles, and demographics to support HR retention strategies.

Address

Ingolstadt, Bayern
Germany

Email

neslihanoztas1@gmail.com

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