Vibe coding for CFOs in fintech.
A fintech CFO closes the books on money that also belongs to customers, and the regulator wants to see that the two piles never mixed. Your reconciliation tool is not a management report but evidence for the safeguarding audit and the capital return, so it has to be correct in a way most finance tools never are.
What is true about software in fintech before you write a prompt.
In financial services, software that touches money or financial records is regulated software, whether it was built by a team of forty or by an executive on a weekend. Fintech companies, lenders, payment businesses and wealth managers all have rules about data, access, records and controls, and a vibe coded tool inherits all of them the moment it connects to a real account.
Money is whole cents, never decimals
Floating-point arithmetic rounds. The AI uses it by default. A ledger, a fee calculation or a payout built that way will be wrong by pennies that add up to an audit finding.
Every action needs a record
Who did what, when, from where. Regulators expect an immutable audit trail, and a homemade tool that lets a record be edited with no history is a control failure.
Credentials are the whole company
A key to the payments provider, the bank feed or the ledger is not a config setting. It is the ability to move money. It lives in a secret store, scoped to the minimum, and never in the code.
Customer financial data has rules about where it lives
Residency, encryption and retention requirements apply. A default database in the wrong region on a free tier is a finding waiting to happen.
What a CFO in fintech builds first.
01Three-way safeguarding reconciliation
Customer balances in the platform ledger, the balance at the safeguarding bank, and the payment processor's settlement report, matched daily with every break listed. Built first because the FCA, the state money transmitter regulators and your auditors all ask for exactly this.
02Fee and interest revenue by product
Interchange, FX margin, subscription fees and interest on float, computed from transaction data in cents and tied to what the processor actually paid out. The processor's dashboard rounds and your ledger cannot.
03Regulatory capital and liquidity monitor
Own funds, safeguarded funds and the required buffer, recalculated each morning from the ledger so you know about a breach on the day it happens, not at the quarter's filing.
CFOs in every industry tend to build the same four things. The CFO page has that list.
The reconciliation auto-clears breaks it cannot explain
The AI builds matching logic that treats any pair of amounts within a few cents as matched, and rolls unexplained differences into a suspense line. The tool reports zero breaks every day. Six months later the safeguarding bank balance is short by an amount that has been silently growing, and you discover it during the auditor's own reconciliation rather than yours.
The pattern underneath is the one every CFO hits: floating-point rounding, a timezone shift on period boundaries, a currency conversion applied twice. The dashboard looks right. It is not, and it has been in the board deck for two quarters.
What a safe build in fintech usually runs on.
Builds run on hosting with the right compliance attestations, Postgres with encryption at rest, single sign-on, secret management from the hosting platform, and Stripe or the company's payment provider through a scoped key. Money is stored as integers. Every write to a financial record is logged with who and when.
What changes for a CFO in fintech.
A CTO in your corner treats your finance tool like the financial system it is. Money is stored as whole cents, never as decimals. Every change is logged with who and when. Credentials are locked away, not in the code. The database has a backup and a tested way to restore it. You keep building the tool only you could design. It just passes the audit.
What CFOs in fintech ask.
A CTO who has read fintech apps before yours.
Thirty minutes, free, no card. What you built, what is going on with it, whether we can help.
In your corner.