Andrzej Leszkiewicz
Power BI and Data Visualization Developer and Consultant
Kraków, Poland
Actions
Andrzej is a Power BI and data visualization developer and consultant, data explorer, explainer, and visualizer.
He is a data visualization enthusiast and the creator of highly customized, interactive visualizations using the Vega visualization grammar and Deneb (a certified custom visual for Power BI).
Andrzej has also introduced high-quality IBCS-styled data visualizations, embedded into Power BI’s built-in Table, Matrix, and Card visuals. He is an IBCS® Certified Analyst and a passionate advocate of IBCS standards.
With a background as an IT project manager and CIO in non-IT companies, Andrzej has been a full-time independent freelancer since 2011, shifting his focus entirely to Power BI and data visualization in 2020.
Through his YouTube channel, LinkedIn, and other social media platforms, Andrzej shares his knowledge and passion for data visualization in Power BI and beyond with the broader community.
Area of Expertise
Topics
IBCS-styled Charts with Just Core Power BI Visuals and DAX
Earlier in 2023, the ability to customize the width and height of SVG images in the Matrix and Table Power BI core visuals was introduced, along with a New Card visual that supports SVG images.
Andrzej Leszkiewicz will demonstrate how these features can be leveraged to create advanced custom data visualizations without the need for custom Power BI visuals.
Andrzej will show how to transform a lackluster and ineffective matrix or table into a highly effective data visualization. He will cover how to embed multiple charts into a table or matrix and how to format the visualization in accordance with the International Business Communication Standards (IBCS) guidelines.
Target Audience:
Power BI report developers eager to learn how data visualizations, created in accordance with the International Business Communication Standards (IBCS), can enhance the interpretability of business reports and how to create them in Power BI using only core visuals (Table, Matrix, New Card) and DAX.
Session Level and Prerequisites:
Advanced. Intermediate to advanced understanding of DAX is advised, as the technique uses DAX to generate SVG code and utilizes calculation groups. A basic understanding of SVG images language will be useful but not necessary. You don't need to know what IBCS is.
Learning objectives:
You'll learn how IBCS guidelines can enhance the interpretability of business reports, how to create IBCS-styled charts without paying for custom visuals licenses by using only core visuals (Table, Matrix, New Card) and DAX, and how to utilize calculation groups to reduce code duplication in your IBCS-styled reports.
IBCS visualizations explained in the session:
https://www.dropbox.com/scl/fi/74j7zy6iiwq38wun7k46f/IBCS_column_chart._Power_BI_Matrix_visual.png?rlkey=2d1g2fdsck1ig070kctt8chvy&dl=0
https://www.dropbox.com/scl/fi/fcyrwh12ew3fdeht59xe1/IBCS_3_tier_chart._Power_BI_Matrix_visual.png?rlkey=mzdn156ks0t3qnexlhz6zzhhy&dl=0
Highly Customized Power BI Visualizations with Deneb and Vega
Andrzej Leszkiewicz is a creator of highly customized and interactive data visualizations using Vega visualization grammar and Deneb custom visuals for Power BI. Andrzej will demonstrate how Deneb and Vega can be leveraged to create advanced custom data visualizations.
Target Audience:
Power BI report developers eager to learn how to create custom data visualizations without learning JavaScript and Power BI visuals SDK. Vega visualization grammar is a declarative language that is relatively easy to learn (it's just a JSON file that describes all visual elements).
Session Level and Prerequisites:
Advanced. If you've already realized that core Power BI visuals limit your data storytelling ideas and you haven't found any existing custom visual that satisfies your requirements, it's time to start using Deneb. Understanding of the JSON format is recommended, and a basic understanding of any programming language will be useful.
Learning Objectives:
You'll learn what kind of possibilities the Deneb custom visual for Power BI and Vega visualization grammar offer and how they can be used to move your data visualization far beyond the limitations of Power BI core and many existing custom visuals. You'll learn how to create simple charts using dozens of Deneb Vega templates, and you'll see how further learning of Vega can help you in creating highly customized data visualizations.
Examples of my Deneb/Vega visualizations:
Deneb Templates: https://github.com/avatorl/Deneb-Vega-Templates/tree/main
Complete report created using a single instance of Deneb: https://powerofbi.org/hr-cross-functional-mobility-rwfd/
Various Vega visualizations: https://powerofbi.org/deneb-vega-data-visualization-examples/
Creating a dashboard using only one visual (Deneb)
In this session, the speaker demonstrates how a single instance of the Deneb custom visual can be leveraged to create an entire report page (dashboard), not just a single chart. This method enables the development of highly customized charts while also facilitating advanced interactions between charts, such as cross-filtering and cross-highlighting.
The presentation shows that creating "highly customized" charts doesn't have to mean making them overly complex or ornamental. Instead, it often involves deep customization to ensure that simple bar charts and heatmaps work together effectively, enhancing data exploration and understanding for end users.
Target Audience:
This session is designed for data visualization professionals who struggle to build comprehensive Power BI reports using various visuals, unaware that a possible solution is to use just one. This session is not for beginners looking to learn how to build their first Power BI reports.
Session Level and Prerequisites:
Intermediate. While a basic understanding of the Deneb custom visual and Vega or Vega-Lite languages is helpful, it is not required. This session may serve as inspiration to start learning them. Instead of a deep dive into "how" (advanced Vega coding), the speaker explains "what" he did and "why" to build this dashboard.
Learning Objectives:
The presentation shows that creating "highly customized" charts doesn't have to mean making them overly complex or ornamental. Instead, it explains that it often involves deep customization to ensure that simple bar charts and heatmaps work together effectively, enhancing data exploration and understanding for end users.
The dashboard that will be demonstrated and explained: https://app.powerbi.com/view?r=eyJrIjoiNzZmOGVlNmItZGNiNC00NGQzLTk1ZmEtYjFlYzA5MDQzZTFiIiwidCI6IjYzNjBkMTZhLTk3MWQtNGQzMC1hOWE5LTdiY2I0ODUzMDhlMSIsImMiOjl9
The Real Power of the New Slicers: Turn Your Slicers into Charts
This session will show you how to take your Power BI reports to the next level by turning charts into interactive slicers. Using the new native slicer visuals, you'll learn how to create slicers that not only filter your data but also display it. Think bar and column charts, maps, or any custom data visualizations, all acting as slicers.
These slicers aren’t just clickable visuals. They support all the features you'd expect from a slicer, like row/column/grid layout; custom formatting for Rest, Hover, Press, and Selected states; default and persistent selection; synchronization across pages; and paginated or continuous scroll overflow.
But instead of using text-based buttons or static images, you will use visuals packed with context to make sure report users don't waste their time randomly selecting contextless slicer items. They will slice for a reason. For example, a user might select a customer because a red variance bar indicates a year-over-year drop in sales, or choose another customer because the bar chart shows they had the highest sales in the previous year.
Who should attend
Power BI report creators, data analysts, and anyone looking to make their reports more interactive and helpful.
Session Level and Prerequisites
Intermediate. You should already be comfortable creating simple Power BI reports, working with native slicers, and writing basic DAX (think VAR, RETURN, CALCULATE, SUMX, CONCATENATEX, SWITCH, ALLSELECTED and so on).
Attendees will learn:
➡️ How to help report users slice for a reason
➡️ How to turn native slicers into interactive charts
➡️ How to use DAX to generate charts (as SVG images)
➡️ How to apply this approach to different chart types, including column charts, bar charts, and maps
➡️ How to add meaning and context to your slicers
➡️ How to improve the appearance and functionality of the slicers
Deep dive into customizing core visuals for clarity and impact
In recent years, Power BI expanded SVG support in Table, Matrix, Card, and Image visuals, as well as Button and List Slicers. Andrzej Leszkiewicz shows how to use SVGs to customize core visuals for clarity and impact. The goal of this customization is not to decorate, but to streamline and unify BI reports.
You'll learn how to build IBCS-guided reports for clearer business insights (IBCS: International Business Communication Standards, see also ISO 24896 Notation for business reporting); how to embed charts into P&L reports; how to turn charts into slicers and slicers into charts; how to make a Top N + Others bar chart without any changes to the data model; and other ways to improve your reports.
With user-defined functions (UDFs) introduced in 2025, report unification through customization is easier than ever. Free open-source UDF libraries let you embed charts into the core visuals just by calling a function.
Take your Power BI visuals to the next level in this hands-on deep dive!
Examples of IBCS-guided data visualizations embedded into Power BI’s core visuals and slicers as SVG images generated by user-defined functions: https://www.powerofbi.org/powerofbi-ibcs-user-defined-functions/
Metareport – Power BI Report of Power BI Reports
Andrzej Leszkiewicz demonstrates how to build a Metareport, a BI report that lists all reports from your workspaces along with their metadata and page thumbnails. You can use it for administrative purposes or leverage the thumbnails to build a user-friendly landing page for report consumers.
The solution uses a Fabric Notebook and the Power BI REST API to prepare data (metadata and thumbnails) and store it in a Lakehouse. The semantic model is connected to the Lakehouse, and the report uses a Button slicer and an Image visual to display the thumbnails.
You will learn how to design and build your own Metareport.
IBCS and ISO 24896 for Better Reports, Dashboards, and Presentations
Andrzej Leszkiewicz will explain the International Business Communication Standards and introduce ISO 24896, Notation for business reporting (an ISO standard currently in development).
He will also show why implementing these standards in reports, dashboards, and presentations improves data understanding and supports data-driven business decisions.
This is a mostly non-technical session that answers key questions: why you need standards, how they work, and what the SUCCESS formula is (a set of seven core principles for designing clear, effective, and standardized business reports and presentations by focusing on message, consistency, density, integrity, visualization, clarity, and logic).
Although the session is non-technical, Andrzej will demonstrate practical examples and share resources for implementing IBCS-guided reporting in Power BI using core visuals and free, open-source code DAX UDF libraries. No custom visuals are required.
You will see how IBCS-guided charts embedded in the core Matrix visual help users familiar with Excel PivotTables (a lot of numbers, no charts) better understand data and recognize the benefits of Power BI, while also helping experienced Power BI users get as much as possible data understanding from core visuals.
Power BI & Fabric Summit 2026 Sessionize Event Upcoming
Power BI & Fabric Summit 2025 Sessionize Event
Power BI Next Step 2024 Sessionize Event
Power BI Cruise 2024 Sessionize Event
Power BI & Fabric Summit 2024 Sessionize Event
Please note that Sessionize is not responsible for the accuracy or validity of the data provided by speakers. If you suspect this profile to be fake or spam, please let us know.
Jump to top