Interviewer: Good afternoon.
Candidate: Hello, Sir, very good afternoon.
Interviewer: Yes, that's another thing and frankly speaking, I forgot about our call, but thanks for reminding me because I'm working on, I was doing multiple things.
Candidate: OK, OK, no problem Sir.
Interviewer: Uh, let me just pull up your profile. Could you please give me a brief overview of where you are currently working and what your day-to-day activities entail? Additionally, could you share information about the size of your team? Are you an individual contributor, or do you have specific responsibilities assigned to you? I'm interested in learning more about the work you are currently engaged in.
Candidate: Thank you for asking about my company and my day-to-day activities. I am currently working at CSM Technology, a highly reputed IT organization in Odisha. We handle approximately 85% of the IT work for the Odisha Government. While it is a private company, our work is closely aligned with the government's requirements.
As a Power Bi Developer, my primary focus is on data analysis. My daily activities involve understanding our clients' problems and finding solutions through data analysis or creating dashboards. To achieve this, we collect data from various sources, which often requires cleaning as the data may not always be in a pristine format. Once the data is clean, we load it into the Power BI environment and establish relationships between different tables. This allows us to identify suitable key performance indicators (KPIs) and create various charts and visualizations to analyze the data further.
After analyzing the data and crafting meaningful insights, we create reports and publish them to our server. Finally, we share these reports or dashboards with our clients to provide them with valuable insights.
In our team, we have a total of 14 members, including myself. It's a relatively small team, which means we collaborate closely and are involved in the entire process, from data collection to report sharing.
Apart from Power BI, we also use other tools like Tableau and SSAS for data analysis. I have experience working with all three tools, allowing me to leverage the best-suited tool for specific analytical requirements.
Interviewer: It says that, OK, so SASS, you're using SASS, you're using Tableau, you're using power BI, right?
Candidate: Yes, Sir.
Interviewer: And what about your experience with SQL and Ms. Excel?
Candidate: When I joined CSM Technology, my role was that of a Database Engineer. So, I have extensive experience working with Microsoft SQL Server and SQL Azure. I can confidently say that I am proficient in SQL 11 and have utilized it in various projects.
As for Ms. Excel, we do use it in our analysis, but I must admit that I don't have extensive experience with it. I am familiar with the basics of Ms. Excel, which are essential for data analysis, but I haven't delved into the advanced features yet. However, I am always open to learning and enhancing my skills further in both SQL and Ms. Excel as needed for my role.
Interviewer: Okay, but what do you know about Excel? Do you have experience with functions like VLOOKUP, IF, and COUNTIF in Excel? Have you worked with these functions before?
Candidate: Yes, sir. I have experience with Excel functions. I am familiar with VLOOKUP, IF, and COUNTIF functions, and I have used them in various projects.
Interviewer: Great! How many projects have you completed using Power BI?
Candidate: I have completed a total of three projects using Power BI. These projects involved creating office dashboards, a quantified dashboard, an IGMS dashboard for a mining project, and a dashboard to represent passport data.
Interviewer: Could you please tell me about the nature of the data you have worked with? What kind of data are you dealing with? Is it financial data, healthcare data, HR data, or something else?
Candidate: The nature of the data that I have worked on includes mining data, HR data, financial data, and citizenship data.
Interviewer: Excellent. Now, let's discuss DAX functions. Which DAX functions have you used in your projects?
Candidate: In my projects, I have used several DAX functions, such as AVERAGE, COUNT, MAX, MIN, SUM, TOPN, ADDCOLUMNS, EXCEPT, GROUPBY, UNION, UPPER, LOWER, and REPLACE, along with various time intelligence functions like DAY, MONTH, YEAR.
Interviewer: Okay, let's consider a scenario where I have a chart showing the count of OC citizens on a monthly basis. For example, in January, the count is 100, and in February, the count is 200. However, when I view the bar chart, the months appear shuffled, like January, March, October, and November. I want them to be in proper order, like January, February, March, and so on. How can I arrange the months correctly in the chart?
Candidate: To achieve the desired order, we can use the "Sort by Column" feature. First, go to the "Data" tab and select the "Month Number" column from the table. The "Month Number" column is an auto-generated column by Power BI, representing January as 1, February as 2, March as 3, and so on. Once you've selected the "Month Number" column, go to the "Modeling" tab and choose the "Sort by Column" option. In the drop-down, select "Sort by month number," and this will arrange the months correctly in the chart.
Interviewer: Impressive! Let's talk about data modeling. How many types of relationships can you create between two tables in Power BI?
Candidate: In Power BI, you can create three types of relationships: one-to-one, one-to-many, and many-to-many relationships.
Interviewer: Correct. Now, suppose you have created a bookmark, but when you switch between pages, your slicer selections are not retained. How can you fix this issue?
Candidate: To fix this issue, you can go to the data tab, select the month number column, go to the Modeling tab, and choose "Sort by column" by selecting the "Sort by month number." This will ensure the month names are sorted properly.
Interviewer: Good. Now, have you worked with the TOPN function in Power BI? Can you explain how to achieve dynamic TOPN using parameters?
Candidate: Yes, I am familiar with the TOPN function. To achieve dynamic TOPN using parameters, you can create a parameter for the desired number of top items. Then, use the TOPN function in your DAX expression and reference the parameter in the "N" argument of the TOPN function.
Interviewer: Excellent. Now, let's discuss query merge and append. What is the difference between append and merge queries?
Candidate: When you append queries, you stack rows from two tables on top of each other, combining them vertically. Merge queries, on the other hand, combine columns from two tables based on matching data, creating a new table with additional columns.
Interviewer: Very good. How many types of joins have you used in Power BI, and can you explain the role of a LEFT JOIN?
Candidate: In Power BI, I have used six types of joins: LEFT JOIN, RIGHT JOIN, INNER JOIN, FULL OUTER JOIN, LEFT OUTER JOIN, and RIGHT OUTER JOIN. The role of a LEFT JOIN is to return all values from the left table and the corresponding matches from the right table. If there is no match in the right table, you see a null value in the result.
Interviewer: Correct. Let's talk about star schema and Power BI. Can you explain how to create a star schema?
Candidate: In a star schema, the fact table is at the center, surrounded by dimension tables. Each dimension table has a single relationship with the fact table, creating a star-like structure.
Interviewer: Good job. Now, let's discuss bookmarks in Power BI. How can you retain slicer selections when switching between pages using bookmarks?
Candidate: To retain slicer selections when switching between pages, you need to enable "Keep all filters" in the bookmark settings. This will maintain the slicer selections across different pages.
Interviewer: Correct. You're doing well. Finally, have you worked with index columns in Power Query, and why do we need them?
Candidate: Yes, I have worked with index columns in Power Query. Index columns are used to assign a sequential number to each row in a table, which helps in organizing the data and improving performance.
Interviewer: Well done. That concludes the interview. Do you have any questions for me?
Candidate: Yes, I do. Can you tell me more about the company culture and any opportunities for growth within the organization?
Interviewer: Sure, our company values teamwork, innovation, and continuous learning. We offer various training programs and opportunities for career advancement based on performance and skills. We encourage employees to take on new challenges and grow within the organization.
Candidate: That sounds great. Thank you for sharing that information.
Interviewer: You're welcome. Thank you for your time and impressive performance in the interview. We will get back to you with our feedback soon. Have a wonderful day!
Candidate: Thank you, Sir. I look forward to hearing from you. Have a great day too. Goodbye.
Interviewer: Goodbye. Take care!
