marble_pond_5529
Warden
Top 7.8%
Member Nº 1208
Joined May 2026
SQL
Correlated Subquery
Window Deduplication
Multiple WINDOWs
Python
Lambda
Unpacking
Dictionaries
Spark
Window Deduplication
Higher-Order Functions
Multiple Windows
Data Modeling
Self-Referential
Junction Tables
Grain Definition
Pipeline Architecture
SCD in Pipelines
Solved
SQL11
Python3
Data Modeling0
Milestones
Hire verdict
10 solved
337 runs in the past 26 weeksActive days: 23 · Max streak: 4
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Recent solves
The Intervals
Python · medium
Suspected Bot Sessions
SQL · easy
Given age = 25 and has_passport = True, using a single compound expression with De Morgan simplifica
Python · medium · lesson
Given a state machine where transitions is {'idle': 'running', 'running': 'done', 'done': 'done'}, s
Python · medium · lesson
Dispatch arithmetic operations through a dict of lambdas
Python · medium · lesson
Use a dict to classify HTTP status codes: map 200 to 'OK', 301 to 'Redirect', 404 to 'Not Found', 50
Python · medium · lesson
Build a decision table mapping (is_member, total >= 100) tuples to discount percentages
Python · medium · lesson
Call the handler function retrieved from the dispatch dictionary.
Python · medium · lesson
Replace an if/elif chain with dict-based dispatch
Python · medium · lesson
Complete the state machine loop: look up the next state from the transitions dict using the current
Python · medium · lesson