Recently, I interviewed a few people for Power BI roles and here are some questions I asked in the initial rounds to assess their skill level. I’ve included sample answers below so you know how to approach such questions.
Prefer video? See this...
I made a video with 10 questions and my (elaborate) answers to them. Watch to learn how to answer such interview questions. See it below or on my YouTube channel.
1. What are the main differences between Power BI Desktop and Power BI Service?
Answer cues:
- Power BI Desktop is the main tool for creating or authoring reports.
- We use PBI desktop to clean up data, create data model, set up measures, build and refine charts and construct the reports.
- We then use Power BI Service to share the reports with the audience.
- Desktop = creation tool, Service = consumption tool
2. Explain the difference between a measure and a calculated column?
- Measures:
- calculate things on top of tables.
- calculated in the run-time based on the evaluation context.
- are usually aggregates.
- example: Shipment Count = COUNTROWS(Shipments)
- Calculated columns:
- are part of the table.
- are calculated at the time of creation based on the row-context.
- have one value per row.
- example: Discount Rate Row-wise calculation of discount rate based on order quantity
- Both measures and calculated columns use the same DAX language.
3. Describe the steps you would take to connect multiple data sources in a Power BI report?
- We can use Power Query to connect more than one source of data.
- We can also use PQ to merge / append / combine the data as needed.
- We can selectively load the data to Power BI and keep the rest in PQ level but customizing the load behaviour.
4. What do 1, * and arrow (â–¶) mean in the data model diagram?
- In a typical star-schema, we will have one to many relationship between dimension and fact table.
- The one side is denoted with a 1 and many side is denoted with a *
- The arrow indicates the direction of filter propagation.
- Power BI allows us to customize the filter direction (uni or bi-directional) and also have many-to-many relationships.
5. What is DAX and give me an example of DAX you've recently used?
- DAX stands for Data Analysis eXpressions. It is the main language of Power Pivot.
- Give examples based on your experiences and tell why / how they helped you solve problems.
6. How do you optimize the performance of a slow Power BI report?
- Answer questions like this based on your experience. If you have never optimized something, be honest and say that. Then give theoretical answers.Â
- Key optimization startegies:
- Reducing the data (filtering at PQ, Source level)
- Removing unwanted visuals, interactions and bookmarks
- Using performance profiler (Optimize ribbon in Power BI) to measure the performance of a page and identifying the problem areas.
- Setting up aggregate tables, pre-calculated views.
- [NEW] Using visual calculations instead of measures.
- Upgrading the Power BI on-prem servers, database servers (for direct query)
- Running time-consuming operations (such as PQ transformations) at low usage times (midnights, evenings)
7. How do you publish a Power BI Report to the service?
- Save and test the report. Make sure all calculations are correct and visuals represent the truth.
- Test any connections, refresh processes too.
- Publish the report (Publish button) and set the correct workspace.
- Test the report on the service view and make sure right people have access to the report.
- Optional, Send an email or share the report with the audience.
8. Explain RLS (Row Level Security) in Power BI?
- Row Level Security allows us to provide access to the relevant data to right people.
- For example, we can use RLS to show only USA data to the USA regional manager.
- We can use “roles” option in Power BI to set and test the roles.Â
9. What is a Slowly Changing Dimension (SCD) and how do you handle it in Power BI?
- SCD (Slowly Changing Dimension) is a dimension (or aspect of a dimension) that changes slowly over time.
- Give examples from your industry or previous work.
- Example: In our product table, we have a feature called cocoa percentage. For certain products this is changed once in a while based on customer feedback. This is an example of SCD.
- We can either replace the old values with new ones or create effective date based records.Â
10. How would you handle missing data?
- We can use either Power Query or Power Pivot to handle missing values in our data.Â
- Power Query shows missing values in a column thru Column Quality feature. We can use this to identify and deal with missing values.
- The key strategies for dealing with missing data are:
- Removing missing values
- Going back to source and fixing the problem
- Replacing missing values with an approximation (imputation)
- Ignoring missing values
Need more help? Watch the video
I made a video with 10 questions and my (elaborate) answers to them. Watch to learn how to answer such interview questions. See it below or on my YouTube channel.
Learn more: Power BI Weekend (2023)
My annual Power BI event – Power BI Weekend is happening this year on November 18 & 19. In this 4 hour event (2 hours on Saturday – Nov 18 & 2 more on Sunday – Nov 19), you will learn the Power BI Essentials to say yes to your next challenge.
The topics covered are,
- What is Power BI? How to use it?
- Power BI vs Power Query vs. Power Pivot
- Understanding Power BI Visual interactions & customizing them
- Data cleanup and transformations with PQ
- Setting up a star schema data model
- Creating and using DAX measures
- Interactive storytelling in Power BI
- Saving & publishing your work
- Resources to learn more
- Q&A with you
Tickets are on sale now. Book yours before they sell-out.
62 Responses to “Introduction to Financial Modeling using Excel [Part 1 of 6]”
Oooh! Chandoo - are you looking to outperform the Altman Z-Score?
I'm all ears 😉
Many thanks, Paramdeep. Looking forward to the remaining parts of the series
Thank you Paramdeep. I look forward to following the series.
Those interested in Financial Modelling may also find this site interesting:
http://www.fimodo.com/
Hi Chandoo,
Really looking forward for this awesome financial modeling journey 🙂
All the very best..
Regards
Rohit1409
Hi Chandoo,
it seems the future is not away when we will have a new software/spreadsheet as competitor to Microsoft Office/Linux etc.......Hats Off to you..
KEEP SMILING
GURU
@apex, clarity: Thanks...
@all: I do hope that you have started creating the model for the simple case given.. Lets see, what according to you all is the best way forward. So your views on the best practices for the template for valuation?
The planning process varies depending on the project and type of data I am looking at.
If I am doing a cost impact study based on actuals, verses a cost impact study to estimate future cost, verses reviewing historical data then creating a model, verse having to review historical data, apply it to a draft model, update the model based on the draft outputs and the presentation then sometimes repeat the process a few times.
Revisions are an absolutely necessary part of corporate financial modeling especially for the presentation sections. A good presentation will be revised multiple time. There are just to many elements which cannot be planned for, especially with ad hoc reports/models.
Revisions are leading cause of errors, and time spent tracking down errors. The more complex the model the more important revision control is. I would be interested in a section on revision control and good methodologies to determine the effect of changes on models. That is without having to due detail review of the whole model over again.
Hi Paramdeep,
I can't wait for the continuation of this series. You have done a great job in making technical terms appear simple and easy to understand. This article is also very useful in our line of business, in fact i will be featuring this article in our site. Of course the credits will go out to you.
Many thanks and keep it up!
Drew
[...] Introduction to Financial Modeling [...]
[...] Introduction to Financial Modeling [...]
[...] Introduction to Financial Modeling [...]
[...] Introduction to Financial Modeling [...]
@Drew: Thanks! Hope that you found the tutorials useful. Feel free to get back with any queries.
[...] you are building financial models or any other type of excel based decision models, chances are, there will be multiple scenarios in [...]
Great information, i also want to learn financial modeling, how to learn
[...] Here is a free financial modeling course to help you get started. Spread some love,It makes you awesome! Tweet [...]
[...] Introduction to Financial Modeling [...]
[...] (if you don’t want to join Financial Modeling School, we are still friends Here is a free tutorial on excel financial modeling.) [...]
chando bhai i m tired for looking financial modeling detail but i cant find it anyway. so plz kindly send me full detail of financial modeling from beginning levelo to final. where i learn complete modeling procedure n order to become professional
You noob, you won`t become a professional like that, you need to do it on your own and learn as you go
@Nadeem Bhai,
The 6 links to the tutorial at the top of this post, build a small integrated financial model step by step. We are also running a complete 8 weeks course on financial modeling (similar to excel school). But that is almost 50% complete right now. If you want to join, you can join the next batch (probably starting in Jan/ Feb)
Feel free to get back, if you have any queries regarding the model/ steps in creating the same
[...] you do not wish to join our course, we are still cool. Here is a 6 part training on financial modeling & 2 part training on project finance. They are free, fresh and [...]
I want to learn how to build a financial model
Dear Lulama,
You can use this tutorial to learn to build a financial model. We also run a course on financial modeling and project finance modeling. The details can be obtained from:
http://chandoo.org/wp/financial-modeling/
You can consider joining that as well.
I would strongly encourage you to join the newsletter to get the updates about financial modeling and the next batch starting for the course.
I want to learn thorough excel and financial modelling thing !!! I am a chartered accountant..CAn you please suggest a detail syllabus that should be learn by me. Also suggest any classes that would cover everything in excel and financial modelling related things.. I stay in mumbai, so please suggest a class in mumbai or any books..byyee.. thanks ..
[...] Financial Modeling using Excel – 6 part tutorial [...]
Hi Vivek,
We do conduct the financial modeling course online as well as in Mumbai. We start with the basics of excel and build a completely integrated financial model in the class. For details you can look at:
http://chandoo.org/wp/financial-modeling/
or
http://www.edupristine.com/courses/financial-modeling/prisitne-fm-offering
Please describe to me various type of financial modela and demonstrate how a model can be build.
Regards,
Dear Immanuel,
This series of articles does exactly that. If you go step by step through the articles and create the excel sheets on your own, you will understand how to create an integrated financial model.
Alternatively, if you are looking for video sessions, you can consider joining our course:
http://chandoo.org/wp/financial-modeling/
It is expected to reopen somewhere in mid july.
[...] Excel Financial Modeling – 6 part tutorial [...]
Thanks Paramdeep this is great!
[...] Few months ago, we learned how to create a project valuation model in Excel as part of our series on Financial Modeling in Excel. [...]
Paramdeep Hi! A bit ignorant here, but let's ask anyway. Can I access "recorded" video sessions apart from following the step by step articles?
Thanks!
@Marius: Yes, we do have a training program with recorded video sessions. If you are interested, you can enroll for the same. The details can be obtained from: http://chandoo.org/wp/financial-modeling/
i want to know about the scope of financial modeling.i also want to know after doing financial modeling course what are the job prospect, like where i can found job so plz send me full detail of financial modeling from beginning levelo to final.
I am interested to join your Financial modelling class cos am involved in a new business. But I have a Macbook Air with Excel for Mac installed. Would that work with your program?
Dear Charsiew,
The complete training program is built using Excel 2007 with MS windows. Though there is nothing specific to Microsoft in the training. I think a few people have joined the program and are using MAC. If you write an email to me on paramdeep @ gmail.com, I can send you the email ids of those participants and you can get to know their feedback and difficulties in using the program.
This is great, when does the next batch start?
Dear Karan,
The course is in recorded format and you can register for the same as soon as you want.Â
Paramdeep, thanks. I'm venturing into financial modelling for the first time and from the little I've read from your website already, I'm sure I'll find your resources very useful; thanks once again.
Dear Seun,
I am glad that you are finding the resources to be useful. Feel free to send in comments with your feedback and further questions.Â
hie ppl...I jst wantd a small favour cn smone help me out in calculating EBITDA, along with its working, from wipros annual report 2011-2012, link -  http://www.wipro.com/investors/annual-reports.aspx
...PLZ plz... i am having a submission tommorow.
[...] [Related: Introduction to Financial Modeling - 6 part tutorial] [...]
Nice article.
In designing Excel Financial Models I design the user interface as friendly as possible and structuring the input variables in the workflow of the client's operations so that they can flow through the impact of the input variables in Excel using buttons and macros and giving the model transparency.
Cheers
Arthur
[…] 4) http://chandoo.org/wp/2010/07/21/financial-modeling-introduction/ Chandoo has a great 6 step guide which goes through financial modeling from start to finish. Includes loads of pdfs to download including cheat sheets and case studies. Definitely a good place to start learning how to get to grips with financial modeling and Chandoo is well known for its Excel tutorials so if anything doesn’t make sense about the terms used to talk about formatting etc. then the answer can surely be found elsewhere on the website (and often already has hyperlinks added to skip straight to those sections as they are talked about within the financial modeling article!) […]
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Another step to build any financial model is to do a financial analysis beforehand. This normally helps to design and come up with good projections.
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