31. Interview Questions Asked in MNC Interviews
31.5 PwC
M46. How is Power BI different from Excel and Tableau?
Reported for: PwC [S11] · also Wipro [S17] [S19], Mu Sigma [S30]
Compared with Excel: Power BI handles far larger data in a compressed model, has a relational star-schema model with DAX, interactive cross-filtering, scheduled refresh, RLS, and sharing through the Service (Excel is still great for ad-hoc analysis and uses the same Power Query and Power Pivot engines). Compared with Tableau: both are leading BI tools. Power BI integrates tightly with Microsoft 365, Teams, Azure and Fabric, and uses DAX. Tableau is known for flexible visual exploration. Give a balanced answer and avoid claiming one is simply "better".
M47. How do you troubleshoot data discrepancies and make sure the numbers are accurate?
Reported for: PwC [S11] · also Tech Mahindra [S25]
Reproduce the number at the source with SQL for the same filters (for example Pune, March 2026, delivered orders only). Then compare step by step: row counts after each Power Query step, relationship issues (blank rows for unmatched keys), wrong grain (order-line vs order), filters or RLS in effect, measure definitions (cancelled orders included?), time zones (UTC vs IST), and refresh timing. Document KPI definitions and keep a reconciliation page or test query.
M48. How would you handle a request for a real-time dashboard?
Reported for: PwC [S11] · also Tech Mahindra [S25]
First ask how "real-time" it must be: seconds, minutes or hourly. Hourly is usually solved with Import and frequent scheduled refresh (the number of refreshes per day depends on the licence). For minutes, use DirectQuery with automatic page refresh on a fast source. For true streaming (live order tracking), use Microsoft's current real-time options (in recent versions this is centred on Fabric Real-Time Intelligence; Microsoft has announced the retirement of the classic real-time streaming semantic models). Also talk about cost and source load.
M49. What are aggregations and how do they help?
Reported for: PwC [S11] · also Accenture [S20]
An aggregation table stores pre-summarised data (for example sales by Date, City and Category) in Import mode, while the detailed Orders table can stay in DirectQuery. With Manage aggregations, Power BI automatically answers summary visuals from the small table and goes to the detail only when needed. This gives fast dashboards on very large data.
Ravindra Bagale's Tip
Friends, pay attention: when a question asks you to compare tools, students often criticise the other tool. Give a balanced answer with a clear reason for your choice. Interviewers value judgement more than loyalty to a product. Don't worry – after doing it two or three times, it becomes a habit.
Ravindra Bagale's Tip – मराठी
मित्रांनो, लक्ष द्या: प्रश्नात tools ची तुलना करायला सांगितलं की students बऱ्याचदा दुसऱ्या tool वर टीका करतात. तुमच्या निवडीचं स्पष्ट कारण देत संतुलित उत्तर द्या. Interviewers ना एखाद्या product बद्दलच्या निष्ठेपेक्षा तुमची विवेकबुद्धी जास्त महत्त्वाची वाटते. घाबरू नका, दोन-तीन वेळा केलं की सवय होते.
Ravindra Bagale's Tip – हिंदी
दोस्तों, ध्यान दो: जब सवाल में tools की तुलना करने को कहा जाए, तो students अक्सर दूसरे tool की बुराई करते हैं. अपनी पसंद की साफ़ वजह के साथ संतुलित जवाब दो. Interviewers किसी product के प्रति वफ़ादारी से ज़्यादा तुम्हारी समझदारी को महत्व देते हैं. घबराओ मत, दो-तीन बार करने पर आदत हो जाती है.