Data & AI Consultancy

Turn Your Data Into Decisions That Scale.

ML Ventures helps growth-stage companies build AI-powered analytics systems, predictive models, and data infrastructure — without the overhead of a full team.

About

The Person Behind the Work

I'm Michael, a mathematician and engineer who found his way into data. I optimized aircraft maintenance scheduling at Southwest Airlines, worked in actuarial analytics at John Hancock, and led revenue analytics at HousingAnywhere before launching ML Ventures.

I hold a BS in Mathematics and Aerospace Engineering and an MS in Econometrics: Quantitative Finance from Erasmus. I've studied across 5 countries and traveled to 65+. SQL clicked for me at Southwest and became the foundation of everything I build.

Today I help small businesses turn messy data into clear decisions, through dashboards that get used, forecasting models grounded in real business context, and pipelines that save hours every week. I combine technical depth with business thinking, and I'm fully AI-native in how I work.

3 degrees

Including an MSc in Econometrics from Erasmus University

65+ countries

Studied across 5, traveled extensively across the rest

4 corporate jobs

Southwest Airlines, John Hancock, HousingAnywhere, Vintus

AI-native

Claude Code in daily development workflow

4 languages

English, Dutch, Mandarin and Japanese

10+ core tools

Python, SQL, dbt, Airflow, Snowflake, Azure, scikit-learn, OpenAI and more

3 service pillars

Dashboards, forecasting and data pipelines

3 continents

Based seasonally across the Netherlands, China and the USA

Services

What I Build

From raw data to production-ready systems. I work across the full analytics stack.

AI Workflow Integration

Connect your existing tools to AI models that actually work. I design and build AI-assisted pipelines — from LLM-powered reporting to automated insight generation — that fit your current stack.

Data & BI Systems

End-to-end analytics infrastructure: data warehouses, dashboards, and reporting pipelines built for decision-makers. Clean, maintainable, and built to grow with you.

Predictive Analytics & ML

Forecasting, classification, and anomaly detection models built from your data. From churn prediction to demand forecasting — deployed and maintained, not just prototyped.

Data Engineering

Pipelines that move, transform, and deliver data reliably. dbt, Airflow, cloud-native ETL — infrastructure you can trust at scale.

Work

Selected Work

Details anonymized per client agreements.

Developer Tool

A premium Windows desktop launcher built for developers. One click opens a full 2×2 Windows Terminal layout, File Explorer, and any startup commands — all configured per project via a dark, theme-able GUI.

  • Instant project environment launch from a single click
  • Per-pane terminal paths and commands, drag-and-drop category management
  • Packaged as a standalone .exe with startup integration
PythonPySide6PyInstallerWindows Terminal
Revenue Reconciliation

Led a full reconciliation of a platform's revenue data across multiple sources, identifying and resolving discrepancies that had gone undetected for months.

  • Traced and resolved revenue mismatches across billing, payments, and bookings
  • Built reconciliation framework used as the ongoing source of truth
  • Enabled accurate financial reporting for leadership and investors
SQLPythondbt
Executive Dashboards

Designed and built automated daily dashboards for executive and finance teams, replacing manual reporting with real-time visibility into core business metrics.

  • Automated daily refresh of KPIs across revenue, growth, and operations
  • Adopted company-wide as the primary decision-making tool
  • Reduced manual reporting effort by several hours per week
LookerSQLdbt
Data Pipeline Engineering

Repaired and stabilized a set of broken data pipelines that were causing inconsistencies across analytics and reporting systems.

  • Identified and fixed root causes of data quality issues
  • Rebuilt pipeline logic for reliability and maintainability
  • Established monitoring and alerting for pipeline health
PythonSQLdbtAirflow
Cloud Data Platform

End-to-end data platform build on cloud infrastructure, from raw ingestion through transformation to analytics-ready outputs for business stakeholders.

  • Architected and deployed a modern data stack from scratch
  • Integrated multiple source systems into a unified data model
  • Enabled self-serve analytics for non-technical teams
SnowflakeAzuredbtAirflowPostgreSQL
ML Prediction Models

Developed machine learning models to predict key business outcomes, delivering actionable insights that directly informed operational decisions.

  • Built and validated predictive models using real business data
  • Delivered predictions integrated into existing workflows and tools
  • Improved decision accuracy for targeted business processes
Pythonscikit-learnSQLOpenAI
Internal Data Tools

Built custom web apps and Excel-based tools to give teams fast, reliable access to data without needing technical expertise.

  • Delivered interactive web apps for data exploration and reporting
  • Created Excel-based tools for teams more comfortable in spreadsheets
  • Reduced dependency on ad-hoc analyst requests
PythonExcelPostgreSQL

Let's Talk About Your Data.

No sales pitch. Just a 30-minute conversation about where you are, where you want to be, and whether I'm the right fit to help.

Book a Free 30-Min Chat →

Michael Castelein

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