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Concurrency
Backend Developer
Concurrency questions
9 questions on Concurrency for backend developers, easiest first.
Easy
1
Duplicate emails despite a check
easy
Medium
1
Optimistic lock update hits 0 rows
medium
Hard
7
Lost update on a wallet balance
hard
One slow route freezes Node.js
hard
Why a lock alone is not enough
hard
Workers block each other on a jobs table
hard
Deadlocks between two transfers
hard
Two doctors go off call at once
hard
Stale value returns after cache delete
hard
