Vladimir N.

Freelance Data Scientist

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Sofia, Bulgaria

Experience

Jan 2020 - Present
6 years

Freelance Data Scientist

Various Clients

  • Conducted ordinal logistic regression analysis examining Big Five personality traits and AI attitudes using Python (mord, scikit-learn), delivering statistical summaries with coefficient interpretations and model diagnostics
  • Developed custom R Shiny applications for psychometric research, survey analytics, and business intelligence
  • Provided statistical consulting expertise in Factor Analysis, reliability testing, and scale development for research projects
Jan 2015 - Dec 2025
11 years

Lead Data & Business Analyst

NERIS Analytics / 16Personalities.com

  • Designed and validated statistical models for personality assessment using Factor Analysis, Item Response Theory, and Structural Equation Modeling
  • Analyzed datasets containing millions of personality test responses using R, SPSS, and custom statistical pipelines
  • Built advanced models using R (lavaan, psych, mirt) for trait measurement, reliability analysis, and predictive modeling
  • Architected and built 16 comprehensive monitoring dashboards covering user behavior, test completion rates, conversion metrics, team performance, technical health, and business KPIs
  • Connected SurveyMonkey to Tableau for automated survey data visualization and analysis, enabling real-time feedback monitoring
  • Developed data-driven strategies using Tableau, Google BigQuery, and custom BI solutions for strategic decision-making and stakeholder reporting
  • Created enterprise-grade internal tools in R Shiny for automated psychometric analysis, reducing analysis time from days to hours
  • Designed and executed large-scale quantitative research studies on personality types and human behavior patterns
  • Built specialized dashboards for team performance monitoring, engagement tracking, and productivity metrics
  • Established best practices for reproducible analysis workflows and statistical validation protocols
  • Technologies: R, SPSS, Tableau, SQL, Google BigQuery, Shiny, ggplot2, plotly, lavaan, psych, mirt, SurveyMonkey API, Git
Jan 2014 - Present
12 years

Founder & Lead Developer

SportPersonalities.com

  • Architected and developed a 183,000+ line codebase in PHP, JavaScript, and SQL with modular design patterns
  • Designed a unified API interface supporting Claude Sonnet 4.5, GPT-4, and Gemini with automatic failover and batch processing
  • Developed an automated athlete personality classification algorithm with 85%+ confidence scoring across four psychological dimensions
  • Built a psychometric quiz generator with a three-phase workflow, quality scoring, and statistical validation
  • Engineered an automated data collection system processing 1000+ athlete profiles from Google Trends, ESPN, and Reddit using the ScrapeOps API
  • Designed a custom MySQL schema with six specialized tables and a caching layer reducing API calls by 90%
  • Implemented a privacy-preserving analytics system with IP hashing, consent management, and right-to-erasure functionality
  • Created an intelligent social media posting system with optimal timing algorithms and an Instagram carousel generator
  • Built a job queue management system (Redis, Bull) handling 100+ concurrent AI requests with status tracking
  • Integrated 11 external APIs (Anthropic, OpenAI, Google, Stripe, Pexels, ElevenLabs, social media platforms) with unified error handling
  • Developed a newsletter campaign system with queue management, GDPR tracking, and automated content curation
  • Implemented caching strategies, database indexing, and lazy loading reducing page load times by 60%
  • Technologies: PHP 8.1+, JavaScript (ES6+), MySQL, WordPress, Claude API, GPT-4 API, Gemini API, GD Library, FFmpeg, Composer, Git
  • Scale: 309 AJAX endpoints, 3,601 functions, 6 custom post types, 50+ articles/week automated generation

Summary

Data Scientist and Full-Stack Developer with 10+ years of experience transforming complex behavioral datasets into strategic insights. Expert in R/Python statistical computing, enterprise Shiny application development, and AI/LLM integration. Led data analytics at NERIS Analytics (16personalities.com), serving millions of users globally with advanced psychometric frameworks. Specialized in building scalable data pipelines, automating analytical workflows, and deploying production ML systems. Combines deep expertise in statistical modeling (Factor Analysis, IRT, Bayesian inference) with modern software engineering practices (API design, cloud databases, containerization).

Skills

Programming Languages

  • R (Expert) - Statistical Computing, Data Visualization, Shiny Development
  • Python (Advanced) - Data Analysis, Ml, Automation, Web Scraping
  • Php (Advanced) - Wordpress Development, Api Integration, Data Processing
  • Javascript/node.js (Intermediate) - Full-stack Development, Async Workflows
  • Sql (Advanced) - Postgresql, Mysql, Bigquery, Complex Queries

Statistical & Ml Methods

  • Psychometrics: Factor Analysis (Efa/cfa), Irt, Sem, Reliability (Cronbach's Α, Omega)
  • Bayesian Statistics: Bayesfactor, A/b Testing, Confidence Intervals
  • Regression: Linear, Ordinal Logistic (Proportional Odds), Diagnostics
  • Machine Learning: Classification, Time Series Forecasting (Prophet), Clustering
  • Text Analytics: Nlp, Sentiment Analysis, Word Networks, N-gram Analysis
  • Business Analytics: Cohort Analysis, Engagement Metrics, Risk Scoring

R Ecosystem & Bi Tools

  • Core: Tidyverse (Dplyr, Tidyr, Ggplot2), Data.table
  • Statistics: Psych, Lavaan, Mirt, Bayesfactor, Lsr, Hmisc
  • Visualization: Ggplot2, Plotly, Googlevis, Qgraph, Rcolorbrewer, Tableau
  • Shiny: Shiny, Shinydashboard, Shinywidgets, Shinyjs, Dt
  • Ml: Prophet, Caret, Mord
  • Bi Platforms: Tableau (Dashboard Design, Surveymonkey Integration), Google Bigquery

Python Stack

  • Data: Pandas, Numpy, Scipy
  • Ml: Scikit-learn, Prophet
  • Web: Streamlit, Flask, Fastapi, Beautifulsoup, Requests
  • Nlp: Nltk, Text Processing

Ai & Llm Integration

  • Models: Openai Gpt-4, Anthropic Claude (Sonnet 4.5), Google Gemini (Flash, Pro)
  • Techniques: Prompt Engineering, Batch Processing, Multi-model Architecture
  • Applications: Content Generation, Data Analysis, Personality Profiling
  • Apis: Whisper (Transcription), Async Workflows, Error Handling

Databases & Cloud

  • Sql Databases: Postgresql, Mysql, Sqlite
  • Cloud: Google Bigquery (Large-scale Data Warehousing)
  • Caching: Redis (Job Queues), Transients
  • Design: Schema Optimization, Indexing, Query Performance

Web Development & Apis

  • Frameworks: Wordpress, Express.js, Shiny, Streamlit
  • Apis: Restful Design, Oauth 2.0, Webhook Integration
  • Frontend: Html5, Css3, Javascript, Ajax, Jquery
  • Integration: 11+ External Apis (Stripe, Scrapeops, Social Media, Ai Services)

Devops & Tools

  • Version Control: Git, Github
  • Containerization: Docker
  • Automation: Cron Jobs, Wp-cron, Task Queues (Bull/redis)
  • Other: Composer, Ffmpeg, Mpdf, Gd Library

Domain Expertise

Psychometrics & Statistics

  • Personality Assessment Design
  • Factor Analysis (Efa, Cfa)
  • Item Response Theory
  • Scale Development And Validation
  • Reliability And Validity Testing
  • Classical Test Theory

Machine Learning & Ai

  • Llm Integration And Prompt Engineering
  • Time Series Forecasting (Prophet)
  • Classification Models
  • Cluster Analysis
  • Nlp And Text Analytics
  • Ordinal Logistic Regression

Data Engineering

  • Etl Pipeline Design
  • Database Schema Optimization
  • Api Design And Integration
  • Async Job Queue Architecture
  • Caching Strategies
  • Web Scraping At Scale

Business Intelligence & Analytics

  • Dashboard Architecture And Design (16 Dashboards)
  • Tableau Dashboard Development
  • Surveymonkey To Bi Integration
  • User Behavior Analytics
  • Engagement Metrics And Kpis
  • Cohort Analysis
  • A/b Testing (Bayesian)
  • Risk Scoring Models
  • Conversion Optimization

Languages

English
Advanced
Bulgarian
Intermediate

Education

Sofia University "St. Kliment Ohridski" - Faculty of Philosophy and History

Master of Arts in Social Psychology · Social Psychology · Sofia, Bulgaria

Sofia University "St. Kliment Ohridski" - Faculty of Philosophy and History

Bachelor of Arts in Psychology · Psychology · Sofia, Bulgaria

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