Backend Engineer - North America Risk Prevention

Job Description The team you will be working with: North America Risk Prevention The North America Risk team is a critical engine within Wise, focusing on our largest and most dynamic market: North America. About the Team Our mission is to protect our customers and the business by staying ahead of financial crime. We handle billions of volume through robust risk and fraud prevention systems that operate at the speed of our customers. What we do • Real-Time Decision Making: We leverage cutting-edge machine learning to run risk assessments instantly, every time a customer uses the calculator (create a quote for a transaction), ensuring a seamless yet secure experience • Enabling Unique Features: We own the risk infrastructure for Instant ACH, one of our most unique and high-value features in the US market. Instant ACH provides instant transfers despite the payment network not supporting that • Cross-Functional Collaboration: Software Engineers, Data Analysts, and Data Scientists collaborate on a daily basis to design new rules, refine ML models, and provide critical support to our chargeback and fraud investigation teams • Future-Proofing: While focused on fraud today, we are expanding our scope to handle comprehensive risk types in the US and Canada, including Sanctions and AML (Anti-Money Laundering) How we work The team is distributed across Budapest and Austin. We work closely with our US-based colleagues to understand the North American market and customer needs, with occasional travel to the US to foster in-person collaboration. What does it take? • 4+ years of experience with Java, Kotlin, or other JVM-based languages, with deep knowledge of the Spring framework. • Obsession with Latency: You can design technical solutions that optimize for both throughput and speed. You understand what it takes to keep p99 end-to-end latency under 1 second for real-time risk & fraud checks, even when handling billions of transaction volumes. • Data & Distributed Systems: Deep understanding of JDBC, database internals, and query optimization. You have hands-on experience with Kafka, Kafka Streams, or Apache Flink to handle real-time event processing. • Infrastructure: Experience with CI/CD pipelines and designing scalable, resilient distributed systems. • Product & User Focus: You prioritize work with the customer in mind, using data to fix pain points (like false positives). You understand that risk checks happen every time a user touches the calculator, and you care about that UX. • Ownership: You take end-to-end ownership of your projects, from the initial idea to monitoring it in production. • Communication: You can articulate complex technical concepts to non-technical audiences. • Cross-Functional collaboration experience: You are comfortable working daily with Data Scientists to put models into production and with Data Analysts to refine rule sets. It is even better if You have • ML Fluency: Since we deploy models for Instant ACH and transaction monitoring, familiarity with machine learning basics: data pipelines, feature engineering, precision/recall. • Data Lake Experience: Experience with OLAP databases or data lakes (like Apache Iceberg) with Kafka ingestion is an advantage. What does success look like? • Impact on Financial Crime: You will understand the specific fraud vectors and how your code directly prevents financial loss while keeping good customers happy. …