Крістіна

Kristina Kosiuk
JUNIOR DATA ANALYST
SUMMARY
Junior Data Analyst specializing in marketing and product analytics, with hands-on experience turning data into
actionable business insights. Skilled in SQL (PostgreSQL, BigQuery), Python, Excel, Tableau, and Power BI, with
experience in data analysis, visualization, and dashboard development. Experienced in marketing performance
analysis, CAC/ROAS/ROMI evaluation, cohort analysis, and A/B testing.

Contacts HARD SKILLS
SQL (PostgreSQL, BigQuery, CTEs, Window Functions)
Python (Pandas, NumPy, Matplotlib, Seaborn)
Phone Data Extraction, Cleaning & Validation
Marketing Campaign Analysis (ROAS, ROMI, CAC, CPL)
[open contact info](look above in the "contact info" section)
Product Metrics & Cohort Analysis (LTV, Retention, Churn)
A/B Testing & Statistical Analysis
Telegram Probability Theory & Mathematical Statistics
Data Visualization & Interactive Dashboarding
Business Metrics Tracking & Unit Economics
LinkedIn Data Storytelling & Insights Generation

Email
[open contact info](look above in the "contact info" section)
WORK EXPERIENCE
Private Practice & Online Schools
Location English Tutor
Lviv, Ukraine September 2024 - now

Taught English to students via private tutoring practice and online language platforms
Developed tailored study programs based on goal analysis, student performance tracking, and knowledge

Tools gap identification
Structured complex language topics into easy-to-understand formats to ensure steady student progress
Achievements:
Systematized student progress tracking, leading to high course completion rates and long-term student
SQL, Google BigQuery retention

Google Looker Studio, Tableau,
PROJECT EXPERIENCE
Power BI
Marketing Performance Tools:
Python (Pandas, NumPy, Dashboard SQL (PostgreSQL), Tableau Public, DBeaver
Description:
Matplotlib, Seaborn) Built an interactive dashboard to analyze marketing channel
efficiency and ad spend ROI, identifying high-performing
campaigns and supporting data-driven budget allocation.
Jupyter Notebook
My tasks:
Google Analytics, Amplitude Data processing and SQL modeling
Marketing KPI calculation & trend analysis
Dashboard development and visualization
Google Sheets, Excel Performance comparison across acquisition channels

Result:
Enabled management to quickly track key marketing metrics

Soft Skills ($28.6M+ spend, 12.2K+ leads) and optimize ad spend allocation

Data-driven decision making User Retention & Cohort Tools:
Analysis SQL (PostgreSQL), Google Sheets, DBeaver
Goal setting Description:
Performed cohort analysis to evaluate user retention dynamics and
Task prioritising compare long-term engagement between organic and promo-
acquired users to optimize marketing spend.

Critical thinking My tasks:
Cohort identification & Retention Rate calculation
Problem solving Interactive cohort tables & heatmap visualization in Google
Sheets
User acquisition channel comparison (Promo vs Organic)
Result:
Language Identified a steep drop in promo user retention (falling to 9–18% by
month 3) compared to stable organic user retention (60–74%)

English - Upper-Intermediate Education
IT School “GoIT”
Data Analysis
Ukrainian - Native March 2026 - now

Ivan Franko National University of Lviv Bachelor of Arts in Translation (Germanic
September 2024 - now Languages)