As the story goes, in 1949 Frank McNamara finished dinner at a Recent York restaurant and found he’d left his wallet in another suit. That card became Diners Club, widely credited as the first multipurpose charge card. It was a piece of cardboard and a promise: the restaurant trusted the card, the card trusted the member, and someone had to make sure the money actually moved.
When a Mercury customer taps their card, the request goes from the merchant’s terminal through an acquirer and a card network to us. In a fraction of a second, we check the balance, apply the customer’s spend controls, screen for fraud and say yes or no. Cards are the way Mercury customers spend money. The Cards Integration team owns the whole Mercury card, not just the swipe: issuance, physical card shipping, spend controls, lifecycle management, authorization, money movement, settlement and reporting, and the infrastructure underneath. We’re looking for a Senior Software Engineer who thinks deeply about systems architecture, cares about the customer experience, and will dive into any problem to move the team forward. Lead projects from idea to tech spec to implementation to launch, working with your PM, EM, tech lead, and teammates at each stage. When you lead a project, it’s yours to see through.
Build features across the stack, from the card experiences customers use to the backend systems that move money.
Help keep our operations excellent. Mentor other engineers and raise engineering quality through design reviews, code reviews, and collaboration.




Work with product, design, operations, risk, compliance, sales, and many other teams.
Have made architectural decisions on complex systems, and be able to explain your reasoning and the trade-offs.
Be excited to put new features in customers’ hands, and care just as much about keeping existing ones working like a charm.
Be comfortable with our tech stack (Haskell and TypeScript) or be ready to learn.
Bonus: experience in fintech, payments, or card issuing.
We encourage you to try our demo site if you’re interested in applying for the role.
*Mercury values diversity & belonging and is proud to be an Equal Employment Prospect employer. All individuals seeking employment at Mercury are considered without regard to race, color, religion, national origin, age, sex, marital status, ancestry, physical or mental disability, veteran status, gender identity, sexual orientation, or any other legally protected characteristic. We are committed to providing reasonable accommodations throughout the recruitment process for applicants with disabilities or special needs. The total rewards package at Mercury includes base salary, equity (stock options/RSUs), and benefits.
Our salary and equity ranges are highly competitive within the SaaS and fintech industry and are updated regularly using the most reliable compensation survey data for our industry. New hire offers are made based on a candidate’s experience, expertise, geographic location, and internal pay equity relative to peers.

📌 Software engineer senior H/F (IT) (Canada)
🏢 Mercury
📍 Canada