Senior BI & Data Consultant

Your reporting doesn't scale?
I fix that.

I help companies and teams that have outgrown their BI setup — I restructure data architecture, semantic models and reporting processes to work efficiently and without friction.

Describe your challenge
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Who I help

I solve specific problems

Reports that can't keep up with the business

Your reporting environment grew organically. Too many workspaces, nobody knows which report is current, and data doesn't match across teams.

Data models that slow everything down

Reports take minutes to load. DAX measures return inconsistent results. The semantic model wasn't designed — it just grew.

Teams that need a senior expert

Your team knows Power BI, but you're missing a senior who can structure the architecture, set standards and guide the scaling.

Processes that still require manual work

Repetitive tasks — exports, transformations, distribution — consume time that should go to analysis and decisions.

Services

What I do

01

Power BI & Semantic Models

I design reports and shared semantic models that serve multiple teams simultaneously — with consistent measure definitions, documentation and standards that maintain order at scale.

02

DAX & Performance Optimization

I diagnose why reports run slowly and fix it at the level of measures, relationships and storage modes. Result: measurable improvement in load times and stability as data grows.

03

SQL & Snowflake

I build the data layer that powers reporting — clean, performant and not dependent on one person. Queries, views and transformation logic in the right place.

04

Reporting Architecture

I organize environments that grew without a plan — workspaces, datasets, permissions, pipelines. Result: a structure where everyone knows what's where and why.

05

Automation & AI Workflows

I automate repetitive processes — exports, transformations, notifications — with n8n, APIs and AI-assisted workflows. Eliminating manual work that slows the team down.

06

Mentoring & Delivery Support

I help teams build their BI capabilities — project onboarding, code review, data work standards. I don't just deliver a solution, I transfer the knowledge.

Facing a similar challenge?

Let's talk
Experience

Where I deliver value

Types of environments and challenges where I bring real value — from architecture cleanup to team support.

Complex reporting environments

Multiple workspaces, shared datasets, complicated permissions — I bring structure and order.

Shared semantic models

Models serving multiple teams — with consistent measure definitions, relationships and naming standards.

Performance issues

Slow reports, heavy DAX queries, inefficient data models. Optimization with measurable results.

Data layer architecture

Clean SQL and Snowflake layer powering reporting. Views, transformations, business logic — in the right place.

Standards & documentation

Data work standards, naming conventions, code review, documentation. Building a quality culture in analytics teams.

Bridging business & technology

Translating business requirements into technical solutions. Working at the intersection of analytics, reporting and IT.

Process

How I work

01

Start with the problem, not the tool

I begin by understanding the business situation and context. Only then do I choose the technical solution.

02

Find the simplest solution

I don't add complexity without reason. The goal: a solution that works and that someone can maintain after me.

03

Build for maintainability

Clean code, documentation, naming conventions. The solution should last years, not weeks.

04

Take ownership of the outcome

I don't just deliver and disappear. I care about performance, scalability and knowledge transfer to the team.

About

Krzysztof Stelmach

I specialize in Business Intelligence, data, reporting and automation. I help organizations make better decisions — through well-structured data, performant models and processes that work without friction.

I combine deep technical expertise — Power BI, DAX, SQL, Snowflake, semantic models — with real understanding of business context and responsible delivery.

I work with teams and organizations that need someone who not only delivers a solution, but also ensures its quality, readability and long-term maintainability.

Technology Stack
BI & Reporting
Power BI Semantic Models DAX Power Query
Data & SQL
SQL Snowflake Data Modeling Performance Optimization
Office & VBA
Excel VBA Access Microsoft 365
Automation & AI
n8n AI-assisted Workflows API Integrations
Tooling
Tabular Editor 3 Git VS Code Docker
Delivery
Reporting Architecture Mentoring Onboarding Documentation
Contact

Let's talk.

Describe your situation — I respond within 24 hours. You don't need a formal brief. A short problem description or question is enough.