Status: IN
Financial systems use domain-appropriate concurrency strategies: wallets use pessimistic sorted locking (guaranteed deadlock-free, zero conflict window) while hotels use optimistic versioned locking (retry on conflict, higher throughput), matching strategy strictness to violation cost.
Wallets can't tolerate any conflict window (money at risk); hotels can retry (inventory contention is less costly)
Depends on (SL): wallet-transfers-are-safe-under-concurrency, hotel-occ-prevents-overbooking