Security Jobs in Web3

About us

Ether.fi is one of the largest crypto companies in the world, with over $10B in assets under management and a team of ~50, almost entirely technical staff. We've been profitable since day one and are focused on building real consumer financial applications.

We believe the future of finance is true on-chain banking. Our products — Stake, Liquid, and Cash — let users earn yield through DeFi strategies and spend their assets globally through our credit card program. You can view our growth publicly on Dune (https://dune.com/ether_fi/etherfi-cash)

Position overview

We're looking for a strong engineer to join credit card transaction team in ether.fi and contribute to the success of credit card program and the risk systems that sit on top of it.

The first pillar is the transaction stack: card authorization and every decline that shouldn't have happened. You will look into what's causing the user frictions based on the declines transactions and come up with pro-active solutions to prevent them.

The second pillar is fraud and risk. Today our defense is largely reactive; you will make it proactive on both sides of the line. Build the rules, monitoring, and internal tooling, and also use them: pull the data yourself, investigate the cases, work out what the attacker actually did, and turn that into the rule that catches it next time.

You'll work closely with Product, CX, and Compliance, and directly with our card program and fraud vendors.

What you'll do

• Improve the card transaction experience: hunt down and eliminate the causes of declines, failed authorizations, stuck holds, and the frictions users actually hit when they spend

• Make the card program better as a product; find where it breaks for real users, propose the fix, ship it

• Hunt fraud and abuse patterns: card testing, cashback farming, merchant abuse, friendly fraud, trial and force-post abuse, multi-account rings

• Own our fraud stack: rules, queues, and scoring logic in Sardine, plus real-time monitoring, alerting, and automated mitigation

• Investigate live cases hands-on; query the transaction data, root-cause the pattern, and propose the rule or control that stops it recurring

• Build internal tools, dashboards, and scripts that make our risk and CX teams dramatically more effective

What we are looking for

• Strong fundamentals in software engineering and problem solving

• 4+ years of professional coding experience, shipping products

• Product sense; you care about the person on the other side of a declined transaction, and you'd rather fix the cause than close the ticket

• Comfortable in the data, not just the codebase; strong instinct to dig into the data by querying it rather than asking someone else to

• Genuine interest in adversarial problems; you find it satisfying to stare at noisy transaction data and spot the pattern that shouldn't be there, then explain why it's there

Plus if you have

• Worked at a fintech, neobank, card issuer, or issuer processor

• Experience on the card issuing side, or with a card transaction processor

• Knowledge of card and payment fraud mechanics: card testing, BIN attacks, friendly fraud, merchant collusion, cashback farming

• Built on a fraud decisioning or transaction monitoring platform, and sat on the operational side of one

• Run fraud investigations or disputes yourself, not only supported the people who do

Perks and benefits

• Competitive salary, performance-based incentives, and token allocation grant

• Opportunity to work on multi-billion dollar products as part of a small team

• Health, dental, and vision insurance plans

• Global team with opportunity for travel and working out of our 3 offices around the world

• 4 weeks work from anywhere

• Exciting company events and team-building off-sites