The Nightmare Data Model Project is Live!
A full data modeling project in Power BI, built from the chaos I have seen in real companies
Hey friends, Happy Tuesday!
Big news today:
🎉 My new Power BI Data Modeling Project is LIVE! 🎉
A complete data modeling project, built exactly like I do in my real projects. We take a nightmare dataset and turn it, step by step, into a clean star schema. Completely free.
And by the way, it happened to me again with this one. Somewhere in the middle, I forgot the camera completely and started talking to you like my colleague, fixing a real problem at a real company. Same story with the SQL data warehouse and the Tableau dashboards:
“For a while, I thought that I’m working at the company. I’m not recording a video and I’m talking to a colleague.”
Yes, I actually said that on camera. 😅
The nightmare dataset
I refused to hand you a clean tutorial dataset. Instead, I collected the ugly scenarios from my real projects and packed them all into one dataset:
23 tables dumped into a stage, and nothing else
Bad shapes, bad relationships, a data model that looks like a spider web
A test customer (999) somebody left behind in the data
Customer data scattered across six different tables
Duplicate products with different codes, quietly waiting to break your numbers
Why so mean? Because there is a high chance that when you join a company, you will open a Power BI project that looks exactly like this. This dataset is my way of preparing you for that moment.
And we clean all of it together. For each step, you pause the video, you do it at your end, and then we continue. From 23 chaotic tables to a healthy star schema. Honestly, with this many facts, it is more like a galaxy.
The skill everyone skips
In my previous roles, I was involved in many Power BI projects that struggled badly. Slow refreshes. Slow reports. And worst of all, wrong numbers.
And after investigating, it was almost never the dashboard. Almost each time, it was the bad model underneath the reports.
The thing is, most people skip data modeling completely. They connect the tables somehow, jump straight to the visuals, and hope for the best. It works for the demo. Then the project grows, the numbers stop matching, and people stop trusting the whole thing. I have seen projects die exactly like this.
Across all my years in data, I met only a few people who can turn a chaos model into a clean one. That is why this skill is going to make you stand out of the crowd.
The rules I want you to keep
The project is full of lessons, but if you only remember five things:
Never connect two facts directly, always put a shared dimension between them.
Protect the number. Put your total sales in a card and know it by heart. Everything you merge into the fact must land on exactly that same number. Mine jumped in the middle of the project (duplicate products), and I caught it in minutes instead of shipping wrong numbers for months.
Every column must earn its place. One single point of truth for each info. In one project we dropped the hash keys from every table and saved around 20% of the dataset. Never be the person who leaves things “just in case”.
Don’t trust until you test. We lock the model with row-level security, then open the report as Nora and check she only sees North America.
So …
If you build this model with me until the end, make it your portfolio project. Share it in LinkedIn, and tag me if you want. And when you get interviewed, talk about this project. This skill is rare.
The next time a spider web data model is staring back at you, you will not panic. You are going to look at it and smile.
Thanks for reading ❤️
Baraa
Also, here are 4 complete roadmap videos if you’re figuring out where to start:
📌 Data Engineering Roadmap
📌 Data Science Roadmap
📌 Data Analyst Roadmap
📌 AI Engineering Roadmap
Hey friends —
Hey, I’m Baraa, a Data Engineer with over 17 years experience, Ex-Mercedes Benz, where I led and built one of the biggest data platforms for analytics and AI.
Now I’m here to share it all through visually explained courses, real-world projects, and the skills that will get you hired. I’ve helped millions of students transform their careers.