๐Ÿ“Š Data Science Chronicles

Welcome to the world of data analysis with Python! ๐Ÿ
Here I share code examples, tips and experiences from real projects.

5+
Years Experience
50+
Projects
100K+
Data Rows
๐Ÿ“š History ๐Ÿ”ฌ Science ๐ŸŒŸ Evolution

๐Ÿ“– The Fascinating History of Data Science

Although data science seems like a modern field, its roots go back centuries. From statistics to machine learning, from computer science to mathematics... Here's the fascinating journey of this interdisciplinary field! ๐Ÿš€

๐Ÿ“Š 1662 - Birth of Statistics
John Graunt analyzed birth and death records, laying the foundations of modern demography.
๐Ÿ“ˆ 1805 - Least Squares Method
Adrien-Marie Legendre established the mathematical foundation for finding the best-fitting line to data points.
๐Ÿค– 1943 - First Neural Network
Warren McCulloch and Walter Pitts developed the mathematical model of artificial neural networks.
๐Ÿ’ป 1962 - "Data Science" Term
John Tukey envisioned the future of data analysis in his paper "The Future of Data Analysis".
๐ŸŒ 1997 - "Data Science" Officially Born
Jeff Wu introduced the term to the academic world with his talk "Statistics = Data Science?".
๐Ÿš€ 2001 - Big Data Era
Doug Laney defined the concept of big data with the "3V Model" (Volume, Velocity, Variety).
๐Ÿ† 2012 - "Sexiest Job of 21st Century"
Harvard Business Review declared data science as "the sexiest job of the 21st century".
๐Ÿค– 2025 - AI and ML Revolution
With the popularization of ChatGPT, GPT-4, and large language models, data science became democratized.
๐ŸŒŸ Interesting Facts:
  • ๐Ÿ“Š Florence Nightingale (1850s): The first "data scientist" who visualized hospital mortality rates
  • ๐ŸŽฏ Netflix Prize (2006): $1M prize competition popularized machine learning
  • ๐Ÿš€ Google MapReduce (2004): Laid the foundation for big data processing
  • ๐Ÿ’ก R Language (1993): Specifically developed for statisticians
  • ๐Ÿ Python's Rise (2010s): Became indispensable for data science with Pandas and NumPy
๐Ÿ“ˆ Data Science Today:
  • 2.5 quintillion bytes of data produced daily
  • 11.5M data scientists worldwide
  • Average salary: $95K - $165K
  • 35% annual growth rate
๐Ÿ”ฎ Future Trends:
  • AutoML and Citizen Data Science
  • Edge Computing and IoT Analytics
  • Ethical AI and Bias Detection
  • Quantum Machine Learning
๐Ÿ”„ Methodology ๐Ÿ“‹ CRISP-DM โšก Agile

๐Ÿ”„ Data Science Project Methodologies

A successful data science project is conducted not only with technical skills, but with the right methodology. Here are the most used approaches in the industry and my experiences from real projects...

๐ŸŽฏ CRISP-DM: The Gold Standard
1๏ธโƒฃ Business Understanding
  • Problem definition and KPI determination
  • Clarifying success criteria
  • Stakeholder alignment
2๏ธโƒฃ Data Understanding
  • Discovery of data sources
  • Exploratory Data Analysis (EDA)
  • Data quality assessment
3๏ธโƒฃ Data Preparation
  • Data cleaning and transformation
  • Feature engineering
  • Train/validation/test split
4๏ธโƒฃ Modeling
  • Algorithm selection and tuning
  • Cross-validation
  • Model comparison
5๏ธโƒฃ Evaluation
  • Performance metrics analysis
  • Business value assessment
  • Model interpretation
6๏ธโƒฃ Deployment
  • Production deployment
  • Monitoring and maintenance
  • Creating feedback loops
โšก My Agile Data Science Approach
# Agile Data Science Sprint Plan (2-week iteration)

## Sprint 1: Data Discovery & Quick Wins
Week 1:
- [ ] Stakeholder interviews and problem definition
- [ ] Data source mapping and access setup
- [ ] Initial EDA and data quality assessment
- [ ] Quick baseline model (simple heuristics)

Week 2:
- [ ] Data cleaning pipeline creation
- [ ] Feature engineering brainstorming
- [ ] First ML model experiments
- [ ] Present preliminary results to stakeholders

## Sprint 2: Model Development
Week 3:
- [ ] Advanced feature engineering
- [ ] Multiple algorithm experimentation
- [ ] Start hyperparameter tuning
- [ ] Cross-validation setup

Week 4:
- [ ] Model performance optimization
- [ ] Model alignment with business metrics
- [ ] Model interpretability analysis
- [ ] Production readiness assessment

## Sprint 3: Deployment & Optimization
Week 5:
- [ ] Model deployment pipeline
- [ ] A/B testing framework setup
- [ ] Monitoring dashboard creation
- [ ] Performance tracking

Week 6:
- [ ] Production deployment
- [ ] Start live monitoring
- [ ] Feedback collection
- [ ] Next iteration planning
๐Ÿ’ผ Real Project Experience: E-commerce Churn Prediction

Problem: Goal to reduce customer churn by 30%

  • Sprint 1: Historical data analysis, 15% baseline churn rate established
  • Sprint 2: RFM analysis + logistic regression, 18% improvement
  • Sprint 3: Random Forest + feature engineering, 28% improvement
  • Sprint 4: XGBoost + hyperparameter tuning, 35% improvement โœ…
Final Results
89%
Accuracy
$2.4M
Annual Savings
๐Ÿ Python ๐Ÿ“ˆ Analysis ๐Ÿš€ Future

๐ŸŽฏ Why Data Analysis?

Guiding the future, finding insights that don't exist in the world, making meaningless chaotic data meaningful. Just thinking about it excites people! ๐Ÿคฉ

๐Ÿ’ก Our Main Goals:

  • ๐Ÿ“Š Transform raw data into meaningful information
  • ๐Ÿ”ฎ Predict future trends
  • ๐ŸŽฏ Make data-driven decisions
  • ๐Ÿš€ Lead innovation
๐Ÿ› ๏ธ Tools I Use:
Python Pandas NumPy Matplotlib Seaborn Scikit-learn
๐Ÿ—„๏ธ MS SQL โšก Performance ๐Ÿ“Š Data Extraction

๐Ÿš€ SQL: The Heart of Data Analysis

Data analysis is unthinkable without SQL! Here's a code example from real projects... ๐Ÿ’ช

๐Ÿ“ D4R Project - Data Extraction Query
SELECT TOP (100) PERCENT 
    derivedtbl_1.adet, 
    derivedtbl_1.event, 
    dbo.table_gunler.tarih
FROM (
    SELECT TOP (100) PERCENT 
        dbo.Table_antep_trabzon_sakarya_events.event,
        dbo.[Dataset 1_SMS_RAW].date,
        COUNT(dbo.[Dataset 1_SMS_RAW].NUMBER_OF_REFUGEE_SMS) AS adet
    FROM dbo.[Dataset 1_SMS_RAW] 
    INNER JOIN dbo.Base_Station_Location 
        ON dbo.[Dataset 1_SMS_RAW].OUTGOING_SITE_ID = dbo.Base_Station_Location.BTS_ID 
    FULL OUTER JOIN dbo.Table_antep_trabzon_sakarya_events 
        ON dbo.[Dataset 1_SMS_RAW].date = dbo.Table_antep_trabzon_sakarya_events.date 
        AND dbo.Base_Station_Location.MX_SAHAIL = dbo.Table_antep_trabzon_sakarya_events.city
    GROUP BY 
        dbo.Base_Station_Location.MX_SAHAIL,
        dbo.Table_antep_trabzon_sakarya_events.event,
        dbo.[Dataset 1_SMS_RAW].date
    HAVING (dbo.Base_Station_Location.MX_SAHAIL = 'GAZIANTEP')
) AS derivedtbl_1 
FULL OUTER JOIN dbo.table_gunler 
    ON derivedtbl_1.date = dbo.table_gunler.tarih
ORDER BY dbo.table_gunler.tarih
๐Ÿ’ก What Does This Code Do?
  • ๐Ÿ“ฑ Combines SMS data with base station locations
  • ๐Ÿข Analyzes specifically for Gaziantep province
  • ๐Ÿ“… Provides historical data sorting
  • ๐Ÿ”— Maintains data integrity with complex JOIN operations

๐Ÿ’ก Tip: This SQL query was developed for the D4R (Data for Refugees) project.

๐Ÿง  ML ๐Ÿ“Š 70/30 ๐ŸŽฏ Training

๐ŸŽฏ Golden Ratio: 70% - 30% Rule

One of the cornerstones of Machine Learning: Splitting data in the right proportions! Here are the tips on how to do it with Python... ๐Ÿ”ฅ

๐Ÿ Python - Data Splitting Operation
# Let's split the data into 70% training, 30% testing
xtrain_70_sms_full = df_sms_full['adet'].fillna(method="pad").head(int(len(df_sms_full)*0.7))
xtest_30_sms_full = df_sms_full['adet'].fillna(method="pad").tail(int(len(df_sms_full)*0.3))

ytrain_70_sms_full = df_sms_full['event'].fillna(value=0).head(int(len(df_sms_full)*0.7))
ytest_30_sms_full = df_sms_full['event'].fillna(value=0).tail(int(len(df_sms_full)*0.3))

# Let's check data dimensions
print(f"๐Ÿ“Š Training data size: {len(xtrain_70_sms_full)}")
print(f"๐Ÿงช Test data size: {len(xtest_30_sms_full)}")
print(f"โœ… Total data: {len(df_sms_full)}")
๐Ÿง  What We Learn From This Code:
  • fillna(method="pad") โ†’ Fill missing data with previous value
  • head() โ†’ Take the first 70% portion
  • tail() โ†’ Take the last 30% portion
  • fillna(value=0) โ†’ Fill missing data with 0
  • int(len()*0.7) โ†’ Calculate 70%
  • int(len()*0.3) โ†’ Calculate 30%
๐Ÿ’ก Pro Tip:

Why 70%-30%? This ratio is the optimal balance for the model to get enough training and provide reliable test results. 80%-20% can also be used for small datasets!

๐ŸŽฏ My Expertise Areas

๐Ÿ“Š Data Analysis & Visualization
Python, R, Tableau, Power BI
๐Ÿค– Machine Learning & AI
Sklearn, TensorFlow, PyTorch
๐Ÿ—„๏ธ Database Management
SQL Server, PostgreSQL, MongoDB
โšก Big Data & Cloud
Apache Spark, AWS, Azure
๐Ÿ“ฑ Web Development
Python Flask, React, API Development

๐Ÿ“š Recommended Resources

๐Ÿ“– Python Data Science Handbook
Jake VanderPlas - Essential data science
๐Ÿ“Š Hands-On Machine Learning
Aurรฉlien Gรฉron - Practical ML
๐Ÿง  Pattern Recognition ML
Christopher Bishop - Advanced level
๐Ÿ”ฅ Deep Learning
Ian Goodfellow - Deep learning bible
๐Ÿ“ˆ Storytelling with Data
Cole Nussbaumer Knaflic - Visualization

๐Ÿ› ๏ธ My Daily Tools

Python Pandas NumPy Matplotlib Seaborn Plotly Scikit-learn TensorFlow Jupyter VS Code Git Docker SQL Server PostgreSQL Redis Apache Kafka AWS Azure

๐Ÿ“ˆ Recent Projects

๐Ÿ›’ E-commerce Analytics Dashboard
Real-time sales tracking and customer analysis
Python, Plotly, Redis
๐Ÿค– Customer Churn Prediction
Customer loss prediction with 89% accuracy
ML, Random Forest, Flask API
๐Ÿ“Š IoT Sensor Analytics
Machine performance and predictive maintenance
Streaming, Kafka, Time Series
๐Ÿ’ฐ Financial Risk Assessment
Credit risk analysis and automated decision system
ML, Feature Engineering, APIs

๐Ÿ’ฌ Get In Touch

If you'd like to discuss data science, machine learning and technology:


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