Build a bank with cashback and history

Extend one banking implementation as payments, delayed events and historical queries are introduced.

Role: Software Engineer
Difficulty: Medium
Practice time: 90 min

The challenge

Build a bank that grows from account operations into spending rankings, delayed cashback, account merges and historical balances. Your implementation carries forward as each level introduces a new requirement.

The difficulty comes from interactions between features. A payment has a later effect, a merge changes where money belongs, and a historical query must still describe the correct moment. Keep those meanings consistent as the same class evolves.

What you'll practise

Time-dependent state
Keep scheduled cashback and requested operations consistent at their boundaries.
Account history
Preserve the meaning of balances and payments as accounts are merged.

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solution.pyPython 3.13

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Build a bank with cashback and history

The challenge

What you'll practise

Time-dependent state

Account history

Build a bank transfer lifecycle

Investigate GPU credit balance drift

Implement an LRU cache

The challenge

What you'll practise

Time-dependent state

Account history

Related challenges

Build a bank transfer lifecycle

Investigate GPU credit balance drift

Implement an LRU cache