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CarlosACrespoS/README.md

Hi, I'm Carlos Arturo Crespo Smith πŸ‘‹

πŸ“Š Data Analyst | Business Intelligence | Statistical Analysis

LinkedIn Email


🎯 About Me

Engineer-turned-Data-Analyst with 5+ years of experience solving the same problem across very different environments β€” a regulated nuclear facility, a state government, and a commercial finance team: valuable information nobody was systematizing. That pattern is where my data practice actually started, years before it had a formal title.

I'm now focused on Data Analyst / BI Analyst roles, remote, on international teams β€” bringing strong business judgment (stakeholder management, identifying what's actually worth measuring) together with a technical stack I'm actively deepening: intermediate SQL (certifying), Python (Pandas, SciPy, Plotly), and Tableau/Power BI.

Every project below follows the same standard: no finding ships without being executed and verified against the underlying data. Where an earlier draft of my own analysis got a conclusion wrong β€” a regional finding in the Megaline project, an unvalidated revenue claim in the Showz A/B test β€” I left the correction in the notebook instead of quietly fixing it. That's part of the deliverable, not a flaw in it.


πŸ› οΈ Tech Stack

Python Pandas NumPy SciPy SQL Streamlit Plotly Tableau Power BI Excel Jupyter


πŸ“‚ Featured Projects

πŸ§ͺ Experimentation & Statistical Validation

Project What it proves
Showz: A/B Testing & Hypothesis Prioritization ICE/RICE hypothesis scoring + Mann-Whitney U validation. Confirms an 18.95% conversion lift (P=0.007) β€” and correctly identifies that a claimed revenue/AOV advantage (P=0.822) wasn't statistically real, a check the original analysis had skipped.
FoodFlow: A/A/B Funnel Validation Bonferroni-corrected Mann-Whitney testing. Pinpointed a 38% funnel drop-off point, confirmed zero A/A control-group bias, and proved a typography change was statistically neutral β€” protecting the business from a false-positive UX decision.

πŸ“Š Business Intelligence & Financial Modeling

Project What it proves
Showz BI: Marketing ROI, Unit Economics & LTV Cohort LTV/CAC/ROMI modeling across 10 acquisition channels. Found a channel absorbing 42.8% of budget while destroying capital (βˆ’$8.29/user, 38.6% ROMI) and a 5x revenue gap between Desktop and Mobile checkout.
Megaline: Tariff-Plan Profitability & Revenue Engineering Rebuilt a 5-table billing engine from raw transactional data. Corrected an initial regional finding after re-testing it β€” NY-NJ underperforms, not outperforms, the rest of the country β€” and isolated a heavy-usage revenue segment within the lower-ARPU plan.
Instacart: Market Basket & Retention Analytics 34.72% of platform traffic concentrated in a 2-day window; a 59.05% baseline reorder rate; and a Day 14–21 churn-risk window mapped for automated CRM retention triggers.

πŸš• Market Research & Competitive Intelligence

Project What it proves
Chicago Urban Mobility: SQL + Weather-Impact Validation SQL data extraction + Levene/t-test validation of a 21.4% weather-driven trip-duration increase (33.3β†’40.5 min, Pβ‰ˆ0.0000) for a rideshare market-entry strategy.
Ice Online Store: Global Video Game Sales & User Score Analysis (confirm repo link before publishing) Mann-Whitney U / t-test validation of rating differences across platforms and genres, plus regional (NA/EU/JP) demand segmentation to guide holiday inventory allocation.

🧱 Foundational Data Engineering & Applications

Project What it proves
Advanced User Data Processing & Segmentation Customer Lifetime Value and cohort segmentation built from raw nested data structures using core Python (no Pandas) β€” isolates high-value under-30 users for VIP targeting.
DQA: Data Quality Assurance & User Profile Structuring An 8-phase defensive ETL pipeline (string sanitization, type casting with exception handling, identity tokenization) turning malformed user records into a production-ready asset.
Urban Music Consumption: Springfield vs. Shelbyville Regional listening-behavior segmentation across 61,253 streaming records, translating day/time engagement patterns into city-specific ad-timing recommendations.
US Used Vehicles Market: Interactive Streamlit Dashboard (confirm repo link before publishing) A live Plotly/Streamlit app over 50,000+ listings, surfacing non-linear mileage depreciation and the 80K–150K-mile core liquidity zone for inventory valuation.

πŸ“« Let's Connect

I'm actively looking for remote Data Analyst / BI Analyst roles on international teams (US/Canada time zones welcome). Open to a conversation.

⚑ Off-screen: board games, the Rubik's cube, chess, and volleyball.

Pinned Loading

  1. ecommerce-funnel-analysis-aab-testing ecommerce-funnel-analysis-aab-testing Public

    Behavioral analytics and A/A/B testing pipeline for FoodFlow. Audits user conversion funnels, validates experiment integrity, and evaluates UX typography changes using Python, Pandas, and SciPy (Ma…

    Jupyter Notebook

  2. sql-python-taxi-weather-impact sql-python-taxi-weather-impact Public

    A data-driven exploration of Chicago's taxi market using SQL and Python. This project identifies top demand hubs and applies statistical hypothesis testing to quantify how weather patterns impact u…

    Jupyter Notebook

  3. video-game-global-insights video-game-global-insights Public

    Global video game sales and user ratings analysis for Ice Online Store. Explores platform lifecycles, regional consumer behaviors (NA, EU, JP), and performs statistical hypothesis testing (SciPy) t…

    Jupyter Notebook

  4. showz-ab-testing-optimization showz-ab-testing-optimization Public

    Hypothesis prioritization (ICE/RICE) and A/B test validation for Showz. Mann-Whitney U confirms an 18.95% conversion lift (P=0.007) β€” and correctly rejects an unvalidated revenue/AOV claim (P=0.822…

    Jupyter Notebook

  5. Showz_Business_Intelligence_LTV_CAC_Analysis Showz_Business_Intelligence_LTV_CAC_Analysis Public

    End-to-end unit economics modeling, cohort LTV analysis, and cross-channel marketing ROI optimization pipeline built in Python.

    Jupyter Notebook

  6. Advanced-User-Data-Processing-and-Segmentation Advanced-User-Data-Processing-and-Segmentation Public

    Automated Python pipeline for processing semi-structured user microdata, aggregating CLV metrics, and extracting multi-dimensional target customer cohorts.

    Jupyter Notebook