Senior Backend Engineer, Trust & Safety

About Polymarket Polymarket is the world's largest prediction market platform. We enable individuals to express views on real-world events by trading on outcomes across politics, economics, sports, culture, and current affairs. Built as a peer-to-peer marketplace with no centralized “house,” Polymarket aggregates diverse opinions into transparent, market-based probabilities that reflect collective expectations about the future. We’re growing fast: both in volume ($21B traded in 2025) and in adoption as an alternative news source. Our ambition is to become a ubiquitous beacon of truth in global media, powered by fast, reliable, and deeply technical market infrastructure. About the role Polymarket is looking for a backend engineer to build the detection, monitoring, and case-management systems that keep our platform compliant and safe at scale. This role partners closely with Compliance, Risk, and Legal to translate regulatory requirements into engineering systems that protect the platform and its users, with high ownership and direct impact on Polymarket’s risk posture. What you’ll do Build detection and monitoring tooling: Design and build detection, monitoring, and case-management systems to meet AML/BSA, KYC/EDD, and sanctions-screening obligations at scale. Integrate surveillance platforms: Build on or integrate with trade-surveillance and case-management platforms (e.g., Eventus, Palantir) and structure audit-grade data pipelines (tiered storage, long-term retention in S3) for compliance and financial-crimes review. Reconcile financial data: Model and reconcile financial data (FinOps, ledger reconciliation) to ensure auditability and accuracy of money-movement records. Partner with Compliance and Risk: Translate regulatory requirements into engineering systems — alerting, case queues, investigative reporting — in close partnership with Compliance, Risk, and Legal. Build real-time risk systems: Develop real-time risk decisioning and transaction-monitoring systems to detect and respond to financial crime. Collaborate cross-functionally: Work closely with engineers across the platform to keep Trust & Safety systems tightly integrated with the broader exchange. What we’re looking for Backend engineering experience building detection, monitoring, or case-management tooling for AML/BSA, KYC/EDD, or sanctions-screening obligations at scale. Experience integrating or building on trade-surveillance and case-management platforms (e.g., Eventus, Palantir) and structuring audit-grade data pipelines. Comfortable modeling and reconciling financial data (FinOps, ledger reconciliation) for auditability and accuracy. Track record partnering directly with Compliance, Risk, and Legal teams to translate regulatory requirements into engineering systems. Background in risk/fraud or compliance-technology engineering at a fintech or crypto exchange (e.g., Coinbase Risk Engineering, Robinhood Financial Crimes). (Plus) Experience building real-time risk decisioning or transaction-monitoring systems at scale. Benefits Competitive salary & equity Unlimited PTO Full Health, Vision, & Dental coverage 401k match Hardware setup — new MacBook Pro, big display, & accessories