About
Arnaud Gastelblum
Freelance data consultant. I design semantic models, build on Microsoft Fabric and Power BI, and use AI every day to deliver faster without cutting corners.
What I do
- Data modeling first. A clean star schema makes everything after it simple: the DAX, the reports, the performance. I’ve been writing about it for years.
- Power BI and Microsoft Fabric. Semantic models, DAX, Fabric warehouses and notebooks, and the tooling that keeps a tenant documented and under control.
- SQL Server roots. T-SQL, SSIS, SSMS: the ground I come from, and still use.
How I work
- Clean, readable code. No redundancy, complexity kept at a level a colleague can follow, performance in mind, and the users always in mind.
- AI as a teammate. I build with Claude Code and Codex together, and I let the AI test what it builds. It writes a lot of the code; the decisions stay mine.
- Organised in Obsidian. Notes, tasks and ideas live in one place, with tools I built for it: Snailkit.
Sharing
I’ve always liked to share what I learn: on this blog, in short videos on my YouTube channel, and at the Club Power BI Brussels meetups and with DataSprouts, a group of Belgian Microsoft data consultants.
I also give tools away: dbt Formatter for dbt models, SSMS in VS Code, Snailkit for Obsidian, a code formatter for DAX and SQL, and LazyDAX to learn DAX.
Why “Lazysnail”?
It started when I mentored a younger colleague. He was anything but lazy or slow, so I playfully called him Lazy snail. The name stayed, for the blog and everything around it.
Outside work
Two kids, Pauline and Antoine, my greatest joys and challenges rolled into one. And running: several marathons and half marathons, for the moment I cross the finish line.
