Anti-Fraud Engineer (Spain)
First seen by Alion on Sep 30, 2026.
About Crossmint
Global financial rails are undergoing a once-in-a-generation transformation. Instant settlement. Programmable. Agent-first. Crossmint is the infrastructure helping companies build for that future.
We are the leading all-in-one stablecoin and wallet infrastructure platform, enabling fintechs, enterprises, and agentic platforms to integrate stablecoin rails with speed, compliance, and scale. Crossmint provides everything enterprises need to ship smart financial rails, including smart wallets, cross-chain stablecoin orchestration, on/offramps, token checkout, and more, all through a single developer-friendly API.
Trusted by more than 40,000 clients including global leaders like MoneyGram, Western Union, and Paga to nation states like the Marshall Islands, Crossmint powers stablecoin flows that move billions from cross-border remittances, global payroll, to the world's first digital UBI program.
MiCA-authorized, PSD2-licensed, and SOC2 Type II certified, Crossmint serves 150+ countries globally across 50+ blockchains. Backed by Ribbit Capital, Franklin Templeton, NYCA, First Round, and Lightspeed Faction.
We're building the infrastructure for the era of programmable finance. Join us!
Location
Madrid (Hybrid), or fully remote from Spain
Type of employment
Full-time
Seniority
5+ years building production systems, with 3+ years focused on fraud, risk, or trust and safety.
Compensation
Base salary range: 95,000 - 125,000 EUR
Note: This range reflects base salary only. Final level, team assignment, and compensation are determined during the interview process based on experience and fit.
Stock options are part of every full-time offer, granted on top of the base salary range above. We want everyone here to be a genuine stakeholder in what we're building.
We conduct two performance reviews annually. The first addresses performance ratings, bonuses, and promotions. The second encompasses these elements along with salary adjustments reflecting inflation and market conditions.
About The Role
We are hiring our first dedicated Anti-Fraud Engineer.
Crossmint moves billions across remittances, payroll, on/offramps, card rails, and agent-initiated payments. Every one of those flows carries a fraud surface, and today the controls live inside each product. This role builds the decisioning layer that all of them use, and owns the numbers it produces.
The role has a loss line attached to it. You will know what fraud costs us, which controls moved that number, and which good customers we blocked on the way. If you want a job where the impact is arguable, this is not it.
You will report to the Engineering Manager for Identity, Compliance & Risk and work day to day with our Risk Operations analysts, Compliance, Legal, Security, and the product teams whose flows you protect. Crossmint operates under MiCA, DORA, SOC 2, and PSD2, so your controls carry both a commercial and a licensing consequence.
This is a hands-on role. You will write the code, read the data, and take the pager.
Responsibilities
Own fraud decisioning
Build and own the services that score and decide onboarding attempts, stablecoin transfers, on/offramp orders, and card transactions.
Turn analyst judgment into production rules and models, with clear thresholds, versioning, backtesting, and a fast path to roll back.
Build the signals those decisions depend on: device, behavior, velocity, counterparty, and graph relationships across clients and wallets.
Measure every decision. Own catch rate, false-positive rate, and fraud loss per product line, and publish them without being asked.
Detect and respond
Build detection for account takeover, mule networks, first-party fraud, synthetic identities, refund and promo abuse, and agent-initiated payment abuse.
Cut the time from a new fraud pattern to a live control. Same day when the pattern is clear.
Lead the engineering side of fraud incidents: contain the loss, find the root cause, and close the hole in the product.
Participate in the on-call rotation.
Give Risk Operations leverage
Build the tools our analysts work in: case management, queues, reason codes, and rule tuning they can do themselves.
Decide what we build and what we buy across device intelligence, transaction monitoring, screening, and case management, then integrate it properly.
Produce the evidence Compliance needs for filings, audits, and supervisory review as an output of the system rather than a manual exercise.
Stay close to the product
Review design documents for new products and name the fraud surface before launch, not after the first loss.
Work with client-facing teams when a client's own fraud problem arrives on our rails.
Keep current on fraud tooling, onchain tracing, and the AI-native workflows we use across engineering.
About You
Must-haves
5+ years building production systems, with 3+ years focused on fraud, risk, or trust and safety.
A track record at a company where fraud carried a real cost: payments, card issuing or acquiring, banking, lending, marketplaces, or a crypto exchange. You can tell us which losses you cut and how you proved it.
Hands-on ownership of a rules engine or model-serving path in production, plus the data pipeline behind it.
Strong programming skills in at least one modern language. TypeScript is ideal.
Fluency in the metrics and the trade-offs between them: catch rate, false-positive rate, precision at threshold, and loss rate.
Comfort with SQL and with running your own analysis. You look at the data before you argue about it.
The judgment to size a control against the loss it prevents and the friction it adds.
Deep familiarity with current AI and agentic tools, and a view on how they change fraud work on both sides.
Bachelor's degree in Computer Science or equivalent professional experience.
Strong plus if you have
Experience with stablecoins, wallet infrastructure, or blockchain payment rails, including onchain tracing and address risk.
Card scheme fraud experience: chargebacks, dispute and monitoring programs, 3DS, and SCA exemptions.
Experience with KYC/KYB onboarding abuse and synthetic identity detection.
Experience with commercial fraud and monitoring platforms, and a clear view of where they stop earning their price.
Experience as the first fraud engineer somewhere, or early in a risk function's life.
Direct experience with BSA/OFAC, PSD2/SCA, MiCA, DORA, or SOC 2.
How to succeed in this role
A successful Anti-Fraud Engineer will:
Ship a control this quarter that shows up in the loss numbers next quarter.
Hold both sides of every threshold: the fraud stopped and the good customer blocked.
Give analysts tools that remove work, rather than a queue that adds it.
Explain one decision to an auditor, a client, and an engineer using the same set of facts.
Find the fraud surface in a design document before the product ships.
This role is not a fit for someone who:
Wants a mature fraud program to maintain. This one is being built.
Tunes models and leaves the product surface to somebody else.
Needs a data team, an ops team, and a platform team in place before shipping anything.
Benefits
Extensive access to leading AI tools and subscriptions, with AI actively encouraged and integrated into daily workflows.
Unlimited, flexible PTO.
Parental Leave program.
Flexible work schedule.
Company laptop and allowance for any necessary home equipment.
Daily stipend for commuting to the office and/or meals.
Two company-paid off-sites each year.
Health + dental insurance.
Our Principles
Results and delivery: Ship high quality work fast.
Build for the long term: Build scalable, secure, and reliable solutions. Use AI.
Extreme Ownership: Be an effective Directly Responsible Individual (DRI). Be proactive.
Be a team player: Be an effective and kind colleague providing credible challenge. Be present and reliable.
Talent research indicates that women are often less inclined than men to apply for a role unless they have experience in 100% of the listed skills. However, this list is only a guide. We welcome your application even if you feel you meet around 75% of the requirements. At Crossmint, we believe skills can be learned, and diversity makes us stronger.
We work to foster a respectful environment where each person can be their authentic self, free from harassment, racism, and any form of discrimination. We proudly uphold our commitment to diversity and inclusion as an equal opportunity employer, and this policy applies to all employment practices within our organization.
Please note that Crossmint never conducts AI-based interviews, and all of our processes include an initial video call with a team member. Crossmint will not request your personal identification documents or any payment at any point during your interview process.
Please stay vigilant about potential fraud. If you receive an email that claims to be from Crossmint but ends with any domain other than @
crossmint.com
, @
crossmint.io
or @
paella.dev
, it is not from us
. We own these three domains listed before, and they are the only legitimate ones.
Please let our Talent Team know if you need any assistance completing any forms, or participating in the process.
Who will be in contact with you
Our People Ops team will be joining you throughout the entirety of the interview and onboarding processes. Feel free to reach out if you need anything!
Adolfo Fernández - Head of People Ops
Gloria Alogo - People Ops, Onboarding & Benefits
Please note that these are the only members of our People Ops team. Please remain vigilant and watch out for impersonators.
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