Alexander Arvidsson

For every hour on stage, a hundred hours of preparation. That ratio stopped feeling like a personal failing when the blog became part of the process — not as a publishing platform, but as a thinking tool. A post forces the argument into shape before the slides exist. If the logic holds on the page, it’ll hold on the stage. If it doesn’t, better to find out now than in front of a sold-out room in Utrecht.

Non-determinism in LLMs creates real operational problems: flaky tests, irreproducible bugs, compliance nightmares, and unreliable agents. Most people only know about token sampling, but randomness creeps in across six distinct layers—from floating-point variance to hidden system prompts. Temperature=0 and random seeds help less than you’d hope because they constrain token selection, not reasoning paths. The solution requires structural constraints, not parameter tuning. Until then, you’re rolling dice in production.

One of the most difficult events to get into for me has always been the Power BI Gebruikersdagen - a.k.a the Dutch Power BI User Days. I’ve always held it in very high regard, and I never stopped submitting in the hopes of one getting to speak. Last year I was invited to deliver a half-day session on presentation skills and a normal one-hour long session on data modeling. I had a blast.

Using Claude Code, I built a full-stack application to replace Microsoft Access - without being a developer or understanding React, TypeScript, or Node.js. LLM-assisted coding enables rapid prototyping and bridges the gap between business requirements and technical implementation, but like flight simulators, it doesn’t make non-developers into developers. The parallel matters: functional prototypes aren’t production-ready systems, and knowing the difference requires actual expertise.

Prompt injection is architecturally unfixable in current LLMs, but defense-in-depth works. Training-time defenses like Instruction Hierarchy, inference-time techniques like Spotlighting, and architectural isolation create practical systems. Microsoft’s LLMail-Inject showed thatadaptive attacks succeed at 32% against single defenses, 0% against layered approaches. Real failures like GitHub Actions compromise prove that securing obvious surfaces isn’t enough. Like SQL injection, it’s manageable with layering.

I’m joining Advania as Lead Data Transformation Architect to build their data practice into something coherent. One of Sweden’s largest MSPs, Advania needs technical foundations that enable real analytics and AI - not just data theater. I’ll lead their direction across Microsoft Fabric, the Azure Data Platform, and hybrid solutions - from feasibility through implementation. The opportunity is building a fresh structure rather than retrofitting onto legacy decisions. This is walking toward work that matters.

The promise of #SNÆCKS trumps the cold and darkness of Oslo in February. Speaking at the third annual Fabric February promises to be a blast just like 2025!

LLMs fundamentally cannot distinguish between instructions and data. Whether you’re building RAG systems, connecting MCP servers to your data platform, or just using AI tools with sensitive information, every retrieved document is a potential instruction override. The Wall Street Journal just proved this by watching Claude lose over $1,000 running a vending machine after journalists convinced it to give everything away for free.