Concurrency
21 practice items · needed by 5 roles
Easy 1Medium 4Hard 16
Practice questions
- Duplicate emails despite a checkeasy
- Optimistic lock update hits 0 rowsmedium
- Lost update on a wallet balancehard
- One slow route freezes Node.jshard
- Why a lock alone is not enoughhard
- Workers block each other on a jobs tablehard
- Deadlocks between two transfershard
- Two doctors go off call at oncehard
- Stale value returns after cache deletehard
- Two buyers, one item lefthard
- Write skew under snapshot isolationhard
- Two agents edit one tickethard
- Jank when parsing a big JSONhard
- Parallel token refresh logs users outhard
- Priority inversionmedium
- Counter shared with an ISRmedium
- Atomic GPIO writesmedium
- A lock-free ISR ring bufferhard
- Garbled log text from two taskshard
- Timestamp jumps backwardshard
- Two writers, one lakehouse tablehard