In May 2026, Marqeta reported its first quarter with GAAP net income, alongside total processing volume of 112 billion dollars, up 33 percent year over year. For anyone preparing for a product manager loop at a card issuing company, that earnings report is a useful study guide. It tells you what the business cares about right now: profitable growth, multi-product expansion, and volume at scale.
Marqeta sits in the issuer processing layer. When a fintech, a bank, or a brand wants to give customers a card, Marqeta provides the platform that creates the card, authorizes each transaction, and moves the money. A PM interview here tests whether you understand that machinery beneath the consumer app. This is how you can prepare for that conversation.
Know where Marqeta sits in the payment flow
Start with the four-party model, because most issuing questions build on that structure. A cardholder pays a merchant. The merchant's acquirer routes the transaction through a card network like Visa or Mastercard. The network sends the authorization request to the issuer, and the issuer returns an approval or a decline. Marqeta is the technology behind that issuer decision.
The company's core product is the issuer processor. When an authorization request arrives, Marqeta's platform checks the balance, applies the program rules, screens for fraud, and returns a response in milliseconds. Its Real-Time Decisioning engine lets a customer write logic that runs inside that authorization window. If you can explain what happens between a card tap and an approval, you have shown the interviewer real understanding of the domain.
Study the difference between issuing and acquiring before the loop. Acquiring serves merchants who accept payments. Issuing serves the businesses who hand out cards. Marqeta lives on the issuing side, so prepare to reason about cardholders, spend controls, and program economics rather than checkout conversion.
Understand the economics behind the platform
Issuer processors earn most of their revenue from interchange. When a cardholder spends, the merchant pays a fee, and a share of that fee flows back to the issuer and its processing partners. Marqeta's take is a slice of that flow. This is why processing volume matters so much in the earnings report: more volume means more interchange.
Bring specifics to the table. In the first quarter of 2026, Marqeta reported net revenue of 166 million dollars and gross profit of 118 million dollars, each up 19 percent from the prior year. Gross profit grew slower than volume, which points to a real tension in the business: large customers negotiate better rates at higher volume. A PM who can name that tension shows commercial judgment.
Expect a question about customer concentration. For years, a single customer, Block's Cash App, drove a large share of Marqeta's volume. The company has worked to diversify, and by early 2026 twelve of its top fifteen customers used the platform in more than one country. If you are asked how you would reduce concentration risk, talk about new verticals, new geographies, and products that deepen each account.
Prepare for the platform and API angle
Marqeta sells to developers, so its PMs think in APIs. Read the public documentation before your interview and learn the core objects: a user, a card, a funding source, and a transaction. Practice describing how a customer would launch a program using those objects. An interviewer wants to hear you speak the language of the people who build on the platform.
Get comfortable with a design prompt. A common format asks you to design an issuing feature, for example a spend control that blocks purchases outside a set category. Walk through the data you would need, the authorization hook that enforces the rule, and the edge cases like refunds and partial captures. Ground the answer in the real authorization flow, and your reasoning will earn the interviewer's trust.
Track the company's direction
Marqeta built its reputation on debit and prepaid programs. In 2026 the company pushed further into credit, buy now pay later, and lending, and it launched a new credit card platform for brands that want embedded credit. It also agreed to support the Mastercard One Credential, which lets a cardholder toggle between secured credit and installments on a single card. Read one recent earnings call and one product announcement so you can speak to this direction.
The company is also folding machine learning into the authorization path. In March 2026 Marqeta added an AI risk score to its Real-Time Decisioning engine, and in May 2026 it named Lukasz Strozek as its new chief technology officer. If a prompt touches fraud, you can discuss how a risk model scores a transaction in real time while keeping approval rates high for genuine cardholders.
Handle the behavioral round with real examples
Every loop includes behavioral questions, and payments companies weigh them heavily because the work involves money, compliance, and other people's trust. Prepare stories about a launch you shipped, a metric you moved, and a disagreement you worked through with a colleague. Use the STAR structure so each story has a clear situation, task, action, and result. Tie at least one story to a regulated or financial product if your background includes that experience.
Ask sharp questions at the end. Good ones for an issuer processor cover the biggest driver of processing volume next year, the balance between debit and credit programs, and how the team measures platform reliability. Questions like these show that you understand the business rather than only the interview.
Your preparation checklist
A Marqeta PM interview rewards candidates who understand issuing as a business and as a technical system. Learn the authorization flow, the interchange economics, and the API objects. Read the latest earnings report and one product launch so your examples carry today's detail. Come in ready to design an issuing feature and to tell honest stories about your own work. Do that, and you will meet the interviewer as a peer who already thinks in the terms of the platform.