Same payment. Same data. Different answers.
Every card payment gets sent to one of several payment companies (PSPs). Today, hand-written rules choose which. We tested whether an AI model, Jev, could choose better. Here you can watch both decide, then change a number and see who flips.
01
Pick a payment
Or enter your own numbers.
02
Watch three routers choose
Two rule books, one AI.
03
Nudge a slider
See if the decision flips.
New to payments? Three terms
- PSP
- Payment service provider. The company that actually moves the money, e.g. a bank or processor. Each charges a fee and approves a different share of attempts.
- Router
- The decision-maker that picks which PSP gets each payment.
- Acceptance rate
- Out of 100 attempts, how many the PSP approves. A cheap PSP that declines a lot loses sales.
STEP 1
Choose the payment
Replaying recorded decisions from the original experiment. Instant and free, so click around.
Worked example
STEP 2
Three routers read the same data
A 44 GBP paymentIdentical input, sent to all three
CurrencyGBP
Methodcard
CountryUK
PSP A approves95%
PSP B approves93%
PSP C approves88%
R1 · RulesLocal rule
Hand-written rule book, first match wins.
CHOOSES
PSP A
Anything else → prefer alpha.
R2 · RulesLocal rule
A second rule book with different priorities.
CHOOSES
PSP C
Anything else → prefer gamma.
Jev · AI modelReplayed from test
Reads the same data and weighs trade-offs it learned from examples.
CHOOSES
PSP B
Confidence 91%
THEY DISAGREE
Jev disagrees with both rule books: PSP B vs PSP C.
Nudge a number and watch who flips.
Open the rule books · the first matching rule wins; the highlighted one decided this payment
R1 · hand-tunedSame numbers in every scenario.
1EUR card payments from Germany, the Netherlands, or France → prefer beta.skipped
2USD transactions → prefer alpha.skipped
3Amount ≥ €500 → pick whichever eligible PSP has the highest observed acceptance rate.skipped
4Amount < €25 → pick whichever eligible PSP has the lowest fixed fee.skipped
5Anything else → prefer alpha.MATCHED
6If the preferred PSP from the rules above isn't eligible for this transaction → fall back to the highest-acceptance eligible PSP instead.not needed
7Safety check: if the preferred PSP's observed availability is below 99% or its observed acceptance is below 88% → fall back to the highest-acceptance eligible PSP instead.not needed
8Whenever two or more eligible PSPs are exactly tied on acceptance or on fee (in any of the rules above that compare them) → prefer whichever has the lower observed chargeback rate, before falling back to a fixed PSP order.not needed
R2 · grid-search tunedTuned for "Stable": large-payment line at €600.
1EUR card payments from Germany, the Netherlands, or France → prefer beta.skipped
2USD transactions → prefer alpha.skipped
3Amount ≥ €600 → pick whichever eligible PSP has the highest observed acceptance rate.skipped
4Amount < €30 → pick whichever eligible PSP has the lowest fixed fee.skipped
5Anything else → prefer gamma.MATCHED
6If the preferred PSP from the rules above isn't eligible for this transaction → fall back to the highest-acceptance eligible PSP instead.not needed
7Safety check: if the preferred PSP's observed availability is below 99% or its observed acceptance is below 85% → fall back to the highest-acceptance eligible PSP instead.not needed
8Whenever two or more eligible PSPs are exactly tied on acceptance or on fee (in any of the rules above that compare them) → prefer whichever has the lower observed chargeback rate, before falling back to a fixed PSP order.not needed
STEP 3
Why Jev chose that
How likely Jev thought each PSP was best
PSP A2%
PSP B94%
PSP C4%
Jev is 91% sure of its top pick.
Sounding sure isn't being right
In the full test, Jev's confidence barely tracked how often it actually picked the better PSP. A 90% answer was not much more trustworthy than a 60% one.
See the calibration chart on Results →STEP 4
What would have happened
SIMULATEDNot from Jev or the real world. Each outcome is a random draw against the PSP's approval rate. Only the routers' picks above are real decisions.
R1 sent it to
PSP A
Approved
Sale kept. Net cost €0.9137.
R2 sent it to
PSP C
Approved
Sale kept. Net cost €0.6095.
Jev sent it to
PSP B
Approved
Sale kept. Net cost €0.7616.