Complete Data Engineer Interview Kit

Everything you need to crack Data Engineering interviews — in one bundle.

177 problems across SQL and PySpark, organized from fundamentals to MAANG-level patterns, plus a visual cheat sheet for last-minute revision.

The Bundle (7 PDFs):

📘 SQL (98 Problems across 3 levels)

1. Level 1: Core SQL — JOINs, Subqueries, Aggregations, NULL handling
2. Level 2: Window Functions, Data Engineering patterns, 10 MAANG Classics
3. Level 3: Performance tuning, Indexes, Partitioning, Distributed Systems

📙 PySpark (79 Problems across 3 levels)

1. Level 1: Architecture, DataFrame API, RDD API, Spark SQL
2. Level 2: Joins & Skew handling, Shuffle tuning, File Formats, Delta Lake
3. Level 3: Performance, Structured Streaming, Production patterns

📗 Cheat Sheet — Quick Reference Card

1. SQL execution order, all JOIN types, window function reference
2. PySpark architecture diagram, DataFrame operations, key configs
3. Data Engineering patterns: MERGE, SCD, watermarks, partitioning
4. Performance cheat sheet: indexes, broadcast joins, caching rules

Why this bundle:

1. Structured progression — not random questions, but a learning path
2. Pattern-based — grouped by interview patterns (Gap & Island, Sessionization, Retention, Funnel Analysis)
3. Input → Output → Solution format for every problem
4. Searchable & offline — Ctrl+F any concept, review anywhere
5. Covers real questions — Leetcode 185, 262, 603 + actual MAANG scenarios