On July 1, 2026, Marqeta began trading on a split-adjusted basis after a one-for-four reverse stock split. Marqeta is one of the largest card issuing platforms, and its stock has drawn attention partly because so much of its volume runs through a single customer, Block. That concentration is a lesson for any payments product manager. Issuing and acquiring look similar from the outside, yet they differ in roles, customers, and money flow. An interviewer will often check whether you can name the side of the network in play.
What each side does
Two businesses sit on opposite ends of a card transaction. The issuer gives the cardholder a card and the account behind that card. The acquirer signs up the merchant and moves the sale into the card networks. When you tap a card at a coffee shop, the merchant's acquirer routes the request to Visa or Mastercard, and the issuer approves or declines the charge.
Issuing platforms like Marqeta, Stripe Issuing, and Galileo let a company launch its own debit, credit, or prepaid cards. Acquiring and gateway companies like Adyen, Stripe, and Fiserv let a merchant accept those cards. Some large companies, Adyen among them, run both an issuing arm and an acquiring arm.
How the money and the incentives differ
The two sides earn money in different ways, and that shapes the roadmap. An issuer earns interchange, the fee the merchant side pays on each purchase, plus interest and card program fees. An acquirer earns a slice of the merchant discount rate, the total price a merchant pays to accept a card. Interchange flows from the acquiring side to the issuing side, so the two roles pull against each other on price.
A PM on the issuing side thinks about card approval rates, rewards, spend, and the economics of each program. A PM on the acquiring side thinks about merchant onboarding, authorization rates, settlement, and cost per transaction. Both care about authorization, yet they see it from opposite ends of the same request.
A quick example shows the split. Say a rideshare company wants to pay its drivers within seconds. On the issuing side, the company works with a platform like Marqeta to hand each driver a branded debit card and load earnings onto that card. On the acquiring side, the same company works with a processor like Adyen or Stripe to take rider payments in the app. One PM owns the outbound card, the other owns the inbound payment, and both report on authorization and cost.
Why the Marqeta story matters for interviews
Marqeta shows why customer concentration is a real risk for an issuing platform. Block, the parent of Cash App, has long been Marqeta's largest customer, and Marqeta has said that Block is shifting some card volume and moving to lower pricing. When one customer drives much of your volume, your roadmap bends toward that customer's needs. An interviewer may ask how you would reduce that dependence, and a full answer covers new verticals, fresh geographies, and pricing that still leaves room for margin.
Adyen offers the contrast. Adyen built direct acquiring that connects to Visa and Mastercard, and it later added issuing, so one company serves both sides of the same merchant. A PM there may own a feature that touches issuing and acquiring at once, which is a different job from a pure issuing role at Marqeta. Knowing that difference helps you tailor each answer to the company on the other side of the table.
Questions you may hear
Interview questions on this topic tend to fall into a few buckets. A product sense question might ask you to design a virtual card program for a delivery startup. A system design question might ask how authorization travels from a merchant terminal to the issuer and returns as a response. A strategy question might ask whether a company should build issuing in-house or buy it from a platform like Marqeta.
When the question is the authorization flow, walk it in order. The cardholder taps, the merchant's terminal sends the amount to the acquirer, the acquirer passes it to the network, and the network routes it to the issuer for a decision. The issuer checks the balance, the fraud score, and the account status, then sends an approval or a decline back along the same path. Settlement happens later, in a batch, when the money actually moves between banks. Interviewers listen for that split between the real-time authorization and the later settlement.
For the build versus buy question, name the specific trade-off. Building issuing in-house means bank sponsorship, network membership, compliance, and a processor, which is a multiyear commitment. Buying from an issuer processor gets you to launch in months, at the cost of some margin and some control. The right call depends on scale, on regulatory appetite, and on how central cards are to the business.
How to prepare
Preparation here is mostly about fluency with the flow of a transaction. Learn the four-party model: cardholder, issuer, acquirer, and merchant, plus the network in the middle. Trace a single fifty-dollar purchase and write down who touches the money and who earns a fee at each hop. Once you can draw that path from memory, most questions become a matter of detail.
Read the public materials from both sides. Marqeta and Adyen both publish clear documentation, and their investor filings explain how each business earns revenue. Match what you read to the role you want, since an issuing PM role and an acquiring PM role reward different knowledge.
Practice out loud with a friend who can play the interviewer. Say the flow, name the fees, and defend a build or buy call until you can do it without notes. The topic rewards repetition more than memorized frameworks.
The Marqeta split is a reminder that these businesses live and die on volume and concentration. If you can explain where the money comes from on each side, and why an issuer and an acquirer want different things, you will handle most questions in a payments loop. That clarity is the real signal.