Leslie Welch

Leslie Welch

I solve problems.

Arlington, Virginia, United States

Leslie Welch is the Principal Fellow of AI & Analytics at Excella with over 16 years of experience in automation, data analysis and visualization, and strengthening organizations’ knowledge of data. Leslie has worked end to end in the data arena from capture and ETL to database design/engineering to analysis and dashboard design. She has extensive experience in enterprise deployment of Power BI, both as an admin and Power BI architect and a trainer and technical community organizer. She is passionate about data governance, truth telling in data, and she creates collaborative environments across data practitioners and the numerous data stakeholders.

Leslie is co-organizer of Power BI DC, and frequently attends and speaks at data community meetups in the DC metro area including but not limited to Data Viz DC, Data Science DC, Women Who Code DC, Washington DC Power Platform User Group, and Generative AI DC. Leslie was recognized as a 2023 New Power Woman in Tech by DCA Live.

Area of Expertise

  • Information & Communications Technology


  • Data Literacy
  • Data Governance
  • Data / Data Ops / Data Governance
  • Data Modeling
  • Data Visualization
  • Data Visualization Tools
  • Azure Data & AI
  • Microsoft Power BI
  • Power Platform
  • Microsoft Power Automate
  • Microsoft Power Apps
  • Azure Data Factory
  • Azure Active Directory
  • Microsoft Fabric

Snowflakes want to be Stars – Moving to the Star Schema in Power BI

Description Coming Soon

Why & how, covers both scenarios - moving from snowflake to star and moving from One Giant Table to star.

Data Model Ideation for Power BI

Description Coming Soon

Walkthrough of the data model ideation process I use to help clients create performant secure data models aligned to a star schema and Power BI performance considerations. Longer talk includes approach to building out medallion architecture technical requirements to enable Power BI data model.

Lost in Translation: Overcoming Data Literacy Gaps

Decision Makers need help in understanding how to use data to improve their strategy. Improving data literacy is key to this.

Data visualization does not provide intrinsic value - the real potential for impact comes from data-informed decision making. The Data Literacy Index shows that large enterprises with higher corporate data literacy — i.e., the ability of a workforce to read, analyze, utilize and communicate data — reap the rewards of a 3–5 % higher enterprise value. Despite this, only 24% of business decision makers are confident in their ability to use data. This talk will discuss pitfalls of data literacy gaps, how to roll out a data literacy program (high level) at an organization and why this should matter to you.

From Chaos to Clarity: Implementing Code Reviews in Power BI

In an enterprise setting, code review of the data models underneath interactive data viz is often overlooked. If you want to avoid wild west style dashboard development, this is a crucial practice to standardize and implement. In addition to enabling easier collaboration on a given dashboard, this process can also educate individual developers on data modeling best practices and increase the overall data viz capacity at an organization. Leslie will show us how she handles code review of Microsoft Power BI data models, some external tools that can help with identifying necessary code changes, and documentation of the code review process.

Familiarity with Power BI data modeling will enable attendees to get more value from this talk.

Demystifying Row Level Security in Power BI

Managing data security is paramount for organizations, even more so for those operating within regulated or government cloud environments. Join us virtually this month for a workshop hosted by Leslie Welch, Power BI DC Co-Organizer and consultant with extensive experience building out and training on Row Level Security (RLS) in Power BI at the enterprise and government levels.

This 1.5-hour workshop is designed to provide Power BI developers, ranging from novices to experienced developers, with a solid foundation to implement RLS in Power BI.

Workshop attendees will learn how to set up RLS start to finish using two approaches, covering setup in both Power BI Desktop the Service. We will tackle some common challenges, discuss model considerations and how they impact RLS, and untangle the differences between access and security in Power BI. The workshop will also address governance considerations and some of the unique challenges present within government cloud infrastructures.

Previous experience in Power BI RLS is not required. Familiarity with data modeling in Power BI helps, but is not required. Familiarity with relational databases will enable attendees to learn something from this session.
Power BI Desktop (still free!) will need to be downloaded prior to session. Power BI Template (*.pbit) will be provided to enable attendees to complete the desktop portion - approximately ~85% of the workshop. Access to a Power BI Workspace will enable attendees to complete the service portion of the workshop.

Dataflows 101

Description Coming Soon

(Power BI / Fabric)
When & Why, how to set up, how to use, how to convert queries in existing reports to use dataflows without breaking everything.

It's a Report - Understanding Power BI Artifacts and When to Use What

Description Coming Soon

reports vs apps vs dashboards vs scorecards
use cases, when to avoid, how to share with data consumers so they don't get lost

Unlocking the Power of Data: A Guide to Effective Viz Presentations

In today's data-informed world, the ability to present information in a clear, compelling way is a game-changer. But how do you go from data overload to a presentation that resonates? Join Leslie for an illuminating talk that will elevate your presentation game. In this session, you'll discover:

Practical pointers that can instantly improve your data viz presentations.
Visual cues that make your data easy to understand at a glance
Why the integrity of your axis labels and scales matters, and how to get them right.
The principles behind embedding visuals that not only capture attention but also reinforce your message.

Whether you're a data viz beginner or a seasoned pro, you'll leave this talk armed with actionable insights to make your next data presentation a hit.

Challenging the Norm: An Agile Approach to Data Visualization

Traditionally, dashboards are developed in a waterfall approach - requirements, data shaping, front end visuals. The data modeling phase can create what is effectively a black box for non-technical stakeholders, with few to no feedback loops. The reality is that most organizations haven’t standardized their metrics and every team works in its own language. Thus, when dashboards are developed without feedback loops to validate assumptions, it can lead to significant rework and model redesign.

In this talk, we'll explore the essentials of adopting an agile approach to data visualization development. The agile methodology promotes iterative cycles and continuous feedback, helping teams align visualizations with organizational goals. We'll walk through real-world examples to demonstrate how this iterative approach not only saves time and resources but also results in more effective, performant interactive reports and dashboards. Attendees will leave with an approach to reduce the rework by introducing feedback loops on both code and visuals both early and often.

Authentication, Access, and Security in Power BI

Description Coming Soon

Overview to detangle what happens where - AAD Service, Power BI Service, and Power BI Desktop

+unique challenges in cross cloud collaboration with multiple government clouds in the mix

Leslie Welch

I solve problems.

Arlington, Virginia, United States