Backend Software Engineer (Senior/Staff)

About Cardless

Cardless is building the infrastructure for the world's best companies to design, build, and launch financial products. Companies like Coinbase and Bilt use Cardless to create credit cards that feel entirely their own. In an industry where branded financial products usually mean shared logos and shared control, Cardless is built to disappear. Our APIs and components shape the journey from the first application to every purchase, reward, and moment of support that follows, while we handle lending, compliance, and operations behind the scenes.

In September 2025, we raised a $60 million Series C led by Spark Capital, bringing our total funding to $170 million. The team is over 70 people and scaling toward profitability by year-end 2026.

We're looking for kind, humble people with high standards and low egos. We take the work seriously without taking ourselves too seriously. We see what could be improved, make it so, and leave every product, system, and team better than we found it.

About the role

Cardless engineers build the infrastructure behind modern credit cards, and backend engineers work on every layer of it: underwriting decisions, ledgers that have to balance to the cent, payment flows, rewards, risk controls, and the APIs our partners build on. We don’t put people in narrow lanes. In a given quarter, you might ship a capability a partner needs before launch day, take a system that works today and make it hold up at ten times the load, or design the foundation for a product line that doesn’t exist yet. We hire for judgment and range. Engineers who reason well about complex systems pick up the domain quickly. Prior experience in payments or lending is a meaningful advantage, but we’d rather bet on how you think than on what’s already on your résumé.

Most fintech backend jobs mean inheriting a mature system and keeping it running. This is your chance to define the system. Over the next few years we’re expanding into new verticals, turning a single-partner platform into a multi-partner one, and replacing infrastructure we rent with infrastructure we own. Those decisions are being made now, and the engineers who join now will make them. You’ll own meaningful pieces of the platform from the start and understand how money moves through a card program from application to statement. You’ll also work with a team that treats correctness as a craft. Engineers who want their work to shape what a company becomes, rather than just keep it running, will find few roles like it.

What you’ll do

• Design and build backend systems that move real money, make credit decisions, and serve hundreds of thousands of cardholders

• Take projects from ambiguity to production: scoping, design, implementation, testing, rollout, and the operational life that follows

• Work across domains rather than inside a single service, going where the highest-value problem is

• Partner with product, risk, compliance, operations, and our partner and vendor counterparts to ship things that hold up in a regulated environment

• Improve reliability, observability, and developer experience as you go, and leave each system better than you found it

What we’re looking for

• Strong systems thinking and problem solving. You can reason about an unfamiliar system, find where it breaks, and make a sound call with incomplete information

• Experience building and operating production backend services, with a track record of shipping projects end to end

• Solid fundamentals in distributed systems, APIs, databases, and infrastructure

• Proficiency in a modern backend language and ecosystem. We are primarily Java with Python for data work, and we do not expect you to have used ours

• Clear communication and genuine care about correctness. A bug here means someone's card declines at the grocery store or their credit report is wrong

How the role grows with level

• Mid-level: You own well-scoped features and services end to end, and you get faster at handling ambiguity with support from senior engineers.

• Senior: You own large, ambiguous projects from design through operation, set the technical approach for your area, and raise the bar for the engineers around you.

• Staff: You set technical direction across domains. That means deciding how the platform scales to many partners, what we build in-house and in what order, and how the core ledger and payments architecture evolves. You shape the decisions other engineers build on.

Bonus Points

• Fintech, payments, lending, or card issuing experience: authorization, ledgers, settlement, reconciliation, disputes, or regulatory work

• Experience with workflow orchestration (Temporal, Step Functions) or event streaming

• You've built and maintained external, partner-facing APIs

Compensation

This role is open at multiple levels. The range below spans mid-level through staff, and where an offer lands depends on the level we calibrate to during the process.

This role has an annual starting salary range of $160,000 - $295,000 + equity + benefits (see below). Actual compensation is influenced by a wide array of factors including but not limited to skills, experience, and specific work location.

Benefits

We're proud to offer our team excellent benefits:

💸 Meaningful Start-up equity

🏥 100% health, vision & dental primary coverage

➕ 75% health, vision & dental dependent coverage

🍱 Catered lunches

🚎 $250/month Commuter benefit

👶 Parental leave

✈️ Team building events & happy hours

🌴 Flexible PTO with a minimum of 15 days off per year

🖥️ Apple equipment

💸 401k plan

Location

We're headquartered in San Francisco, CA, with a beautiful office in Jackson Square. We’re in the office at least three days a week, and most of us are there more than that, because we do our best thinking and building together in person. We’re looking for someone who’s genuinely excited to be there alongside the team.