Post #2587

🔹 DATA ANALYST – INTERVIEW REVISION SHEET 1️⃣ Role Clarity > “A data analyst collects, cleans, analyzes data, and converts it into insights that help businesses make decisions.” 2️⃣ SQL (Most Important) Must-know clauses: • SELECT, WHERE, ORDER BY, LIMIT • GROUP BY, HAVING • JOINS (INNER, LEFT) • Subqueries, CTEs • Window functions (ROW_NUMBER, RANK) Golden rules: • WHERE → before aggregation • HAVING → after aggregation • LEFT JOIN → keeps all left table rows • NULLs break calculations → use COALESCE Classic questions: • Top N per group • Find duplicates • Running totals 3️⃣ Excel Essentials Formulas: • IF, XLOOKUP • COUNTIFS, SUMIFS • TRIM, LEFT, RIGHT Core features: • Pivot tables • Conditional formatting • Data validation (dropdowns) Avoid: • Merged cells • Hard-coded values 4️⃣ Power BI / Tableau Concepts: • Data model (star schema) • Relationships (one-to-many) • Measures > calculated columns Must-know DAX: • Total Sales = SUM(Sales[Amount]) • YTD Sales = TOTALYTD(SUM(Sales[Amount]), Sales[Date]) Design rules: • KPIs on top • One story per dashboard • Minimal visuals 5️⃣ Statistics (Only What Matters) • Mean vs Median • Standard deviation • Correlation ≠ causation • Outliers distort averages • Use median for Salaries, House prices 6️⃣ Data Cleaning (Interview Gold) Steps you should say: 1. Remove duplicates 2. Handle missing values 3. Fix data types 4. Standardize text 7️⃣ Business Metrics • Revenue • Growth rate • Conversion rate • Churn • Retention • Average order value Always connect metrics to business impact. 8️⃣ Case Question Framework (Very Important) Always answer like this: 1. What happened 2. Why it happened 3. What should be done Example: > “Sales dropped due to lower traffic in one region, so I’d recommend increasing marketing spend there.” 9️⃣ Project Explanation Template > “The goal was . I used to clean data, to analyze, and to visualize. The key insight was . The business impact was .” Memorize this. 🔟 HR Power Answers Why data analyst? > “I enjoy finding patterns in data and turning them into actionable insights.” Strength: “I combine technical skills with business understanding.” Weakness: “I used to over-analyze, but now I focus on impact.” 🧠 Last-Day Interview Tips • Think out loud • Ask clarifying questions • Don’t jump to tools immediately • Focus on impact, not syntax 💬Tap ❤️ for more!