Query Writing & Optimization Ability to write clean, efficient SQL queries and optimize them for performance across large datasets.
Data Extraction & Transformation (ETL) Skilled in extracting raw data, cleaning it, and transforming it into structured, analysis‑ready datasets.
Joins, Subqueries & Window Functions Mastery of advanced SQL logic to handle complex analytical tasks and multi‑table relationships.
Database Schema Understanding Strong ability to interpret and work with relational database structures, constraints, and relationships.
Exploratory Data Analysis (EDA) Using SQL to profile datasets, detect anomalies, validate data quality, and prepare insights.
Aggregation & Reporting Building summary tables, KPIs, and analytical views to support dashboards and business decisions.
