Vibe coding for purchasing managers in fintech.
You buy for a lender, a payments business or a wealth firm, where a vendor is a third-party risk the regulator expects you to manage and document. The tension is that your vendor file is also the outsourcing register examiners ask for, so the tool you build to speed up buying has to produce evidence, not just decisions.
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 purchasing manager in fintech builds first.
01The third-party risk register
Every vendor scored by criticality, data access and financial exposure, with due diligence documents and the next review date. Built to answer the examiner's request in a day instead of a month of email archaeology.
02The data processor map
Which vendors receive customer financial data, what fields, in which region, under which agreement. Regulators and enterprise clients both ask, and the ERP has no field for it.
03The subscription and market data reconciler
Bloomberg terminals, data feeds, licence seats and API call tiers matched against who still uses them. Market data is often the second biggest non-payroll cost and the easiest to overpay.
Purchasing managers in every industry tend to build the same four things. The purchasing manager page has that list.
The risk register can be edited with no history
A vendor's criticality gets downgraded to skip a review, or a due diligence date is quietly changed. The AI built plain update forms with no version history, so the register shows the current value and nothing else. At the next examination the register is a finding, and the team cannot show whether the change was a fix or a cover-up.
The pattern underneath is the one every purchasing manager hits: the dashboard has no login or one login for everyone. Negotiated rates, contract terms and supplier margins are one shared URL away from a competitor or a supplier's rival.
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 purchasing manager in fintech.
A CTO in your corner treats your procurement tool as a control, not a convenience. Approvals are enforced on the server where they cannot be skipped. ERP access is read-only until there is a reason for it not to be. Supplier documents are private and pricing is behind a login with roles. You still build the tool purchasing has needed for years. It just passes the audit it was built to help with.
What purchasing managers 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.