Interview Guide

Recently Asked Power BI Developer Interview Question at Indegene As a Power BI enthusiast or developer, interview questions often delve into the technical intricacies of DAX (Data Analysis Expressions). Here’s a deep dive into a commonly asked question, recently posed to a 2+ year candidate for the Power BI Developer role at Indegene. 1. What is the difference between ALL, ALLSELECTED, and ALLEXCEPT functions? Understanding these functions is key to managing filters effectively in your calculations. ALL ➡️ Removes all filters applied to a table or column, including slicers, visuals, and external filters. Example: DAX TotalSalesWithoutFilters = SUMX(ALL(Sales), Sales[Amount]) If filters are applied to Region and Product, using ALL(Sales) ignores both. One-liner: Removes all filters from the data. ALLSELECTED ➡️ Removes filters inside a visual but respects filters from slicers or external visuals. Example: DAX SalesInSlicerContext = SUMX(ALLSELECTED(Sales), Sales[Amount]) If a slic...

Power BI Gateways – Real-Time Insights & Interview Tips As a Power BI developer with 3 years of hands-on experience, I’ve encountered several scenarios requiring efficient use of Power BI Gateways. These tools are vital for enabling secure data transfer, especially when connecting on-premises data sources to Power BI for real-time or scheduled insights. What are Power BI Gateways? A Power BI Gateway acts as a bridge that facilitates secure data movement between on-premises sources (e.g., SQL Server, Oracle, Excel) and the Power BI service. Gateways ensure seamless connectivity and enable real-time or scheduled data refreshes, helping organizations make data-driven decisions. Real-World Use Case In one of my recent projects, I configured an On-Premises Data Gateway to provide real-time updates for a client’s sales dashboard. The dashboard sourced data from a SQL Server database hosted on the client’s internal network. This implementation enabled: Live Data Access: Sales teams cou...

PwC Data Analyst Interview question and its answer PwC Data Analyst Interview Experience (1–3 Years) Are you preparing for a data analyst role at PwC or a similar organization? Here’s my recent experience tackling some challenging SQL and Python interview questions during the selection process for a PwC Data Analyst role. These questions test both foundational knowledge and problem-solving skills. Here's how I approached them. SQL Questions 1. How Indexing Works in SQL Indexing improves query performance by allowing faster retrieval of rows. A clustered index organizes data physically, while a non-clustered index uses pointers to rows. Choose columns frequently used in WHERE or JOIN clauses for indexing, like CustomerID in a Transactions table. 2. Identify Customers with Purchases in Consecutive Months Using window functions: sql WITH ConsecutivePurchases AS ( SELECT CustomerID, MONTH (TransactionDate) AS TransactionMonth, YEAR (TransactionD...

My Wells Fargo Data Analyst Interview Experience (1–3 Years) CTC: 16 LPA As a data enthusiast and SQL aficionado, I recently tackled some challenging SQL and Python questions in a Wells Fargo interview for a Data Analyst position. The experience was both rewarding and insightful. Here’s how I approached these questions. SQL Questions 1. Identify Inactive Accounts To identify accounts inactive for more than 12 months: sql SELECT AccountID, CustomerID, Balance FROM Accounts WHERE LastTransactionDate < DATEADD( YEAR , -1 , GETDATE()); This query filters accounts where the LastTransactionDate is older than one year. 2. Top 3 Accounts by Transaction Volume Per Month Using ROW_NUMBER() to rank accounts by total transaction volume for each month: sql WITH MonthlyVolume AS ( SELECT AccountID, SUM (Amount) AS TotalVolume, MONTH (TransactionDate) AS TransactionMonth, YEAR (TransactionDate) AS TransactionYear FROM Transactions GROUP...

How I Would Solve These Tricky SQL Questions Asked in American Express Interview SQL is a fundamental skill for any data analyst, and mastering complex queries is key to standing out in interviews. Below, I break down how I would approach solving the tricky SQL questions mentioned. Each of these challenges is designed to test both your technical proficiency and your problem-solving ability. Let’s dive into the solutions. 1. Find the Second-Highest Salary in a Table Without Using LIMIT or TOP This is a classic problem that requires creativity. My solution: sql SELECT MAX (salary) FROM employees WHERE salary < ( SELECT MAX (salary) FROM employees); Here, the subquery finds the maximum salary, and the outer query selects the highest salary below that. 2. Find All Employees Who Earn More Than Their Managers Joining the table to itself is the key here: sql SELECT e1.employee_name FROM employees e1 JOIN employees e2 ON e1.manager_id = e2.employee_id WHERE e1.salary > ...

How I Cracked the Data Analyst Role at Flipkart 🚀 The journey to securing a Data Analyst role at Flipkart was both challenging and rewarding. Here’s a detailed walkthrough of my experience, preparation strategy, and key takeaways. Application Process Applied Through: LinkedIn Total Number of Rounds: 5 HR Discussion: Focused on my past roles, experiences, and suitability for the position. 1st Technical Round: Covered foundational concepts in Excel, Power BI, and SQL. 2nd Technical Round: Delved into complex SQL queries and advanced Excel-based problem-solving. Managerial Round: Scenario-based questions to assess analytical thinking and problem-solving in real-world situations. Final HR Discussion: Discussed roles, responsibilities, and expectations from the role. My 3-Month Preparation Strategy 📆 Month 1: Advanced Excel, Power BI, and Data Visualization Source: Pavan Lalwani 🇮🇳 Excel for Data Analysis: Excel was the backbone of my initial preparation. I focused on the followi...

BlackRock Data Analyst Interview and Answer BlackRock’s Data Analyst interview process is known for its intensity and focus on technical expertise, especially in SQL and Python. The questions were a mix of practical problems, theoretical knowledge, and real-world financial scenarios, reflecting BlackRock's emphasis on analytical rigor and financial acumen. Here’s a breakdown of the questions I encountered and my approach to solving them. SQL Questions 1️⃣ Identify customers who have invested in at least two funds with opposite performance trends over the last 6 months. Answer : sql WITH FundPerformance AS ( SELECT FundID, CASE WHEN AVG ( Return ) > 0 THEN 'Increasing' ELSE 'Decreasing' END AS Trend FROM FundReturns WHERE Date >= DATE_SUB(CURDATE(), INTERVAL 6 MONTH ) GROUP BY FundID ), CustomerInvestments AS ( SELECT CustomerID, FundID FROM Investments ) SELECT ci.CustomerID FR...