Security Engineer

As a Security Engineer at Coinflow, you own the day-to-day defensive and offensive security posture of a next-generation payment service provider. You'll build the SecOps backbone, hunt for weaknesses in the stack before anyone else does, and partner with engineering to keep the secure development lifecycle fast and secure. This role reports to the CTO and connects directly across the engineering organization.

What you'll do

• Stand up and operate the SIEM, building a SecOps dashboard that gives engineering, compliance, and leadership real-time visibility into security posture, alerts, anomalies, auth events, infrastructure changes, and audit-ready evidence.
• Run continuous internal penetration tests against Coinflow services, APIs, infrastructure, and embedded SDKs, using Claude Security and Claude Code to scale coverage across reconnaissance, fuzzing, code review, and exploit development.
• Own the vulnerability lifecycle end-to-end, triaging CVEs across npm, cargo, and other ecosystems, and building automation to keep packages patched without breaking production.
• Monitor and improve the secure development lifecycle by defining secure-by-default patterns for new services, reviewing threat models for high-risk changes, and integrating SAST/DAST and secret scanning into CI.
• Work with the compliance function to produce evidence, controls, and monitoring artifacts that PCI DSS, SOC 2, ISO 27001, and DORA auditors require.
• Review, troubleshoot, and triage security and application issues to ensure safe, secure, and efficient services for customers.

What you bring

• 4+ years in a security engineering, product security, or DevSecOps role, ideally at a fintech, payments company, or other regulated environment.
• Strong hands-on offensive skills demonstrated by breaking real systems, not just running scanners, with comfort across web app, API, cloud, and infrastructure penetration testing.
• Production experience operating a SIEM such as Datadog, Splunk, Elastic, or Panther, and building dashboards that engineers actually use.
• Fluency in TypeScript/Node and at least passing comfort with Rust, Go, or Python enough to read code, find bugs, and write tooling to automate finding more.
• Experience with vulnerability management at scale, including CVE triage, SCA tooling, and dependency upgrade automation.
• Comfort working with AI-native tooling such as Claude Code or Claude Security as a daily driver, or genuine excitement to learn.
• Proven technical skills and understanding of complex technology architectures across different cloud hosting providers.
• A bias toward shipping: you prefer a working v1 of a control today over a perfect v3 next quarter.

What we offer

• Base salary of €80,000 to €100,000 EUR, depending on experience, education, skills, qualifications, and business needs.
• An equity grant allowing you to share in the long-term success of the company.
• Health and wellness benefits, 401(k) savings plan, and flexible time off.

About Coinflow

Coinflow is a next-generation payment service provider built for the $194 trillion cross-border payments market. Founded in 2023 and headquartered in Chicago, Coinflow enables businesses to grow faster with instant settlement, fraud and chargeback indemnity, global pay-ins, multi-currency FX, and unified payouts. The company has achieved 23x revenue growth since its seed round in 2024 and announced a $25M Series A in October 2025 led by Pantera Capital, CMT Digital, Coinbase Ventures, Jump Crypto, and Reciprocal Ventures.