John Success Lazarus — Data & BI Analyst

~/what I do

Freelance BI work and full-time roles, same skill set: turning raw, messy data into something a non-technical stakeholder can act on.

build-dashboard

Power BI and Tableau dashboards that replace a folder of spreadsheets with one report people actually check.

clean-pipeline

Python and SQL pipelines that take exports full of duplicates and gaps to an analysis-ready table.

segment-customers

RFM segmentation and churn analysis to show who's loyal, who's about to leave, and why.

consult

Ad hoc quantitative consulting through the GLG expert network for one-off questions and due diligence.

~/projects

ecommerce-segmentation github.com/jsonlaz/E-Commerce-Analysis

python analyze_customers.py

loyal customers

96% of users (38,433)

churn detected

-53% over 4 months (3,012 customers)

payments

40% of transactions by credit card

top category

Books, +52% vs. lowest-performing category

stack — Python · SQL · Power BI

tech-stock-performance github.com/jsonlaz/Tech-Stock-Performance-Analysis

python stock_analysis.py --tickers AAPL MSFT TSLA NVDA

tickers

AAPL, MSFT, TSLA, NVDA

finding

steady compounding growth vs. high volatility

output

risk/return dashboard for hypothetical portfolios

stack — Python · yfinance · Tableau

dsmc-method github.com/jsonlaz/DSMC-Method

python dsmc_simulation.py

method

Direct Simulation Monte Carlo (DSMC)

domain

rarefied gas / particle dynamics modeling

approach

stochastic, particle-based numerical simulation

stack — Python · NumPy · scientific computing

imdb-eda github.com/jsonlaz/IMDB-EDA-Project

python clean_and_explore.py

dataset

IMDB movies

steps

cleaning, deduplication, missing-value handling

output

exploratory analysis of ratings, genres, and trends

stack — Python · Pandas · EDA

~/experience

2026.06 — present

Expert Consultant

GLG (Gerson Lehrman Group)

Advising clients and private equity firms on quantitative methods, market intelligence, and data workflows.

2025.11 — present

Mathematics & Computer Science Teacher

Emmaus Christian School, Maenza, Italy

Teaching and assessing students across a UK-certified curriculum, adapting explanations to different learning levels.

2024.10 — 2025.11

Sports Data Analyst

Genius Sports, Karlstad, Sweden

Validated high-frequency live sports data under strict timing constraints at 99.8% accuracy, feeding analytics used by betting operators and media.

2020.04 — 2022.02

Technical Support Assistant

Vigor Protocol (remote, Web3)

Resolved client tickets, tracked recurring issues to their root cause, and built a self-service FAQ and knowledge base.

2019.04 — 2019.09

Data Analyst Intern

National Bureau of Statistics, Abuja, Nigeria

Cleaned, validated, and helped automate reporting for national Sustainable Development Goals statistics.

// also: top editor at IQwiki (formerly Everipedia), 500+ articles written and edited

~/skills

skills/

├── languages/ Python (Pandas, NumPy, SciPy, scikit-learn) · SQL · R · Excel (Power Query, XLOOKUP)

├── visualization/ Power BI (DAX) · Tableau · Matplotlib · Seaborn

├── analysis/ RFM segmentation · churn analysis · time series · EDA · ETL

├── automation/ Web scraping (BeautifulSoup, Scrapy)

└── spoken/ English (native) · Italian (A2 → B1, in progress)

~/education & certifications

education

MSc Mathematics

Karlstad University, Sweden — 2024

MSc Mathematical Engineering

University of L'Aquila, Italy — 2024

BSc Mathematics

Anchor University, Lagos, Nigeria — 2020, Best Graduating Student

certifications

ML & AI Foundations: Prediction, Causation & Statistical Inference

NASBA — 2026

Advanced SQL, SQL for Data Analysis, Excel Essentials

LinkedIn Learning — 2025

Forward Program

McKinsey.org — 2025