What a replacement must preserve in a payment application.

Application review

The bill-payment path settles the current positive balance

Source finding. The payment handler checks confirmation, reads the account and rejects a non-positive current balance. On the confirmed payment path, it copies the current balance into the transaction amount, writes the transaction and then subtracts that amount from the account balance before updating the account.

Engineering consequence. Calling this simply “make a payment” leaves a material choice unstated. A replacement that introduces an arbitrary payment amount has changed this path’s behaviour. That may be desirable, but it should be an explicit business decision with corresponding requirements.

Review required. Establish whether the target should retain balance settlement or introduce partial payments. Separately examine transaction consistency, concurrent requests and recovery if processing is interrupted between the related writes.

Source checked: COBIL00C: payment handling. This check establishes the code path; runtime recovery has not been exercised here.

Application review

A card update protects against a stale view

Source finding. Before rewriting the card record, the update path compares the latest values with the values retained from the earlier read. Differences in the checked card fields cause it to leave the update path and ask the user to review the intervening change.

Engineering consequence. A conventional read–edit–save API can remove this protection if it blindly overwrites the current record. The replacement can look correct to one tester and still lose another user’s change.

Review required. Decide which fields form the concurrency boundary and how conflicts reach the caller. A proposed acceptance check uses two sessions: one saves a change, then the other attempts to save its older view. The expected result must include both retained data and the user-visible conflict.

Source checked: COCRDUPC: update and comparison. The two-session check is proposed verification, not a reported test result.

Application review

Source review corrects the draft as well as validating it

The earlier public summary left zero and negative balance handling unresolved. The payment handler contains an explicit check. This page corrects that summary against the pinned public source.

A genuine operational unknown and an error in generated documentation must not be treated as the same kind of finding. The complete generated specification remains subject to review; these selected checks do not amount to acceptance of the whole application.

Application review

Make the first slice useful before introducing financial writes

A read-only enquiry can test access, account mapping and the display contract while leaving balance-changing operations for a later slice. That gives the team an initial integration boundary to examine.

Before introducing writes, the plan needs resolved payment semantics, concurrency handling and an agreed recovery model. Migration review must include record compatibility and reconciliation, including rejected transactions. A new technology stack does not answer those questions.