A slick pitch deck and a signed NDA tell you almost nothing about whether a software partner can be trusted with your fintech stack. Most vendor questionnaires are built for generic software risk, not the specific weight of handling regulated financial data.
The real evaluation starts after the sales call ends, in detail most vendors would rather not put in writing.
The stakes are higher in a regulated industry, where the wrong partner doesn't just slow you down. It becomes something a regulator can ask you to explain, sometimes years after you sign the contract.
TL;DR
Generic vendor checklists miss fintech-specific risk,
Access matters more than promises,
Vendor evidence should be ready for regulators on demand,
Some work should never leave your own team.
What should a vendor risk assessment actually check?
Every fintech has its own risk appetite, and that shapes what "vetted" means for a given company.
Dennis Overbeeke, CTO of the Dutch fintech New10, runs every new vendor through a Change Risk Assessment.
"If we want to use a new vendor, we do a Change Risk Assessment. Doing a CRA on a third party tells you that we have requirements for each third-party vendor that we want to integrate or work with." — Dennis Overbeeke, CTO at New10
That review has to be specific to the company doing it, not a generic checklist. The same logic applies to any fintech software development partner being brought into a regulated environment.
The World Economic Forum's Global Cybersecurity Outlook 2026 found that 74% of more resilient organizations assess supplier security maturity, compared to just 48% of less resilient ones.
That gap is where a lot of fintech vendor decisions go wrong unnoticed.
How much access should a partner get to your data?
Overbeeke splits vendor requirements into two buckets, technical and business.
"It might be on the tech side, like what kind of encryptions you're using, or on the business side, what kind of processes you have in place or what subcontractors you are working with." — Dennis Overbeeke, CTO at New10
Encryption standards and subcontractor use aren't details to confirm once and forget. They're the two questions that tend to expose whether a partner has thought about fintech data security, or is just saying the right words.
TSH's own work on Cleeng's Adyen payment integration shows what custom financial software development looks like in practice.
The build leaned on the principle of least privilege, encrypted data at rest through AWS KMS, and kept credentials isolated in a dedicated secrets manager.
That's the kind of vendor risk assessment answer worth asking any partner for before a contract gets signed.
Can you prove what your vendors have access to on demand?
Marilyn McDonald, CTO at Thredd, frames this as a readiness test, not a compliance checkbox.
"The harder question is whether you have visibility into your estate: where AI is being used, what vendor tools are in play, what's in-house, and what data each tool can access." — Marilyn McDonald, CTO at Thredd
If a regulator walked in tomorrow and asked for that inventory, could you hand it over in an afternoon, or would it take weeks to reconstruct it?
McDonald is blunt about which side of that line most companies are on.
"Most regulation requires evidence, and if a regulator walks in and asks for your AI inventory, that needs to be an easy report to pull. If it's a nightmare to produce, you're not ready." — Marilyn McDonald, CTO at Thredd
Vendor-supplied financial software development services make this harder, not easier.
It's difficult for a buyer of a third-party system to reproduce the internal evidence behind someone else's model in full, which is why you have to control the boundary of what data goes in and out from your side.
What should stay in-house versus outsourced?
Every CTO uses outside help somewhere. McDonald doesn't pretend otherwise.
"Any CTO who says they never use external vendors either works somewhere I've never worked or isn't being straight with you. The question is what you delegate to them and what stays internal." — Marilyn McDonald, CTO at Thredd
Her line is accountability, not skill level.
Work that a regulator would need a named, internal owner for stays in-house. Everything else can be delegated to move faster.
McDonald aims for something close to a 70-30 split between employees and contractors as a baseline, with room to stretch that ratio in a genuine emergency.
But she adds a nuance. A senior external partner embedded with a team for years stops being external in any real sense. That distinction is worth keeping in mind whenever a fintech software development partner is brought in to extend the team rather than replace it.
How do you evaluate a partner without slowing everything down?
Rigorous vetting and speed sound like opposites, but Overbeeke pushes back on that framing.
"Don't see compliance as a burden. It's a necessary part of being a CTO in financial services." — Dennis Overbeeke, CTO at New10
The teams that struggle aren't the ones with the strictest requirements. They're the ones treating every vendor review as a one-off negotiation instead of a repeatable process, regardless of which fintech development company is on the other side of the table.
A CRA that's already defined doesn't need to be reinvented for the next software development partner under consideration. It just needs to be run.
That's what turns partner evaluation from a bottleneck into infrastructure you reuse every time a new vendor shows up.
How do you know if a partner can actually be trusted?
Different CTOs start from different places, but they share one instinct. The ones who trust their partners fastest are the ones who built a process before they needed one.
Define your own risk appetite before you evaluate anyone against it,
Ask what a partner must access, not just what they say they'll deliver,
Keep the evidence trail ready before a regulator ever asks for it.
A good software partner will welcome that scrutiny. One that resists it has already told you most of what you need to know.
The interview with Dennis Overbeeke, CTO, New10.
The interview with Marilyn McDonald, CTO, Thredd.
Authors
Adrian Senecki
Copywriter and budding fiction writer, interested in (but not limited to) the business side of software development. Likes acquiring new skills and foretelling the future.
Andrzej Wysoczański
Frontend developer with 10 years of experience. With The Software House for almost 7 years, going from a regular dev to the Head of Frontend. He loves keeping tabs on the latest frontend technologies, especially React-related. Regular of the Taby & Spacje podcast (tsh.io/taby-vs-spacje) for Polish speaking programmers.