ahmed_selim

data engineering

Savant

Top 0.9%

Ahmed Selim

Member Nº 4634

Joined Aug 2026

SQL

Correlated Subquery

Existence Checks

Ranking

Python

Frequency Counting

Guard Clauses

Dict Methods

Spark

Window Frames

Window Deduplication

First & Last Values

Data Modeling

Indexing

Metric Additivity

Constraints

Learned

SQL291

Python233

Milestones

Top 100

Steward

7-day streak

1,419 runs in the past 26 weeksActive days: 23 · Max streak: 10

MayJunJulAugSepOct

Recent solves

Filtering: Advanced

SQL · medium · lesson

Filtering: Advanced

SQL · medium · lesson

Filtering: Advanced

SQL · medium · lesson

Filtering: Advanced, Regex operators and patterns Challenge 4

SQL · medium · lesson

Filtering: Advanced, Regex operators and patterns Challenge 2

SQL · medium · lesson

Filtering: Advanced, Regex operators and patterns Challenge 5

SQL · hard · lesson

Filtering: Advanced, REGEXP_LIKE patterns Challenge 1

SQL · medium · lesson

Filtering: Advanced, REGEXP_LIKE patterns Challenge 3

SQL · hard · lesson

Filtering: Advanced, NOT IN vs NULL gotchas Challenge 3

SQL · medium · lesson

Filtering: Advanced, NOT IN vs NULL gotchas Challenge 2

SQL · medium · lesson