Real-Time Ledger Caching Consistency | Dataford Interview Questions

Architect a robust caching mechanism for a business banking application that displays real-time transaction ledgers while ensuring data consistency.

Implement process_ledger_events(events, capacity). Each event is either ['update', account_id, version, transactions] or ['read', account_id, minimum_version]. An update replaces an account's cached ledger only when its version is newer. A read returns [version, transactions] only when the cached version is at least minimum_version; otherwise return None. Evict the least recently used account when the capacity is exceeded. Return results for read events in order.

Constraints

1 <= len(events) <= 10^5
1 <= capacity <= 10^4
Each event is a valid update or read event
Account identifiers are non-empty strings
Versions are positive integers
Update versions for an account may arrive out of order
Transaction snapshots are lists and must be returned unchanged

Function Signature

def process_ledger_events(events, capacity):

Your question is Real-Time Ledger Caching Consistency. Start with the requirements in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.

Problem

Architect a robust caching mechanism for a business banking application that displays real-time transaction ledgers while ensuring data consistency.

Constraints

1 <= len(events) <= 10^5
1 <= capacity <= 10^4
Each event is a valid update or read event
Account identifiers are non-empty strings
Versions are positive integers
Update versions for an account may arrive out of order
Transaction snapshots are lists and must be returned unchanged

Function Signature

def process_ledger_events(events, capacity):

Your question is Real-Time Ledger Caching Consistency. Start with the requirements in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.