Senior Application Security Engineer

Hi, we’re MoonPay. We’re here to onboard the world to the decentralized economy by making digital money move as universally and effortlessly as the internet. Because crypto, stablecoins and blockchain aren’t just technologies. They’re tools for global financial empowerment. They give people and businesses more control over their money, their digital assets, and their future, opening access to legacy financial systems that have been out of reach for many. MoonPay is a unified payments platform for digital currency. We make it easy for anyone, anywhere, to buy, sell, swap and pay in digital currencies as easy as sending an email. That simplicity is intentional, our focus is reducing complexity so people can participate confidently, without needing to be crypto experts. We power the entire flow between fiat and crypto end to end, with compliance, identity checks, fraud prevention, and settlement all built in. This end-to-end approach reflects how we work internally: with accountability, rigor, and trust built into everything we ship. Trusted by over 30 million customers and over 500 ecosystem partners, our secure, enterprise-grade platform is driving mainstream crypto adoption worldwide. Behind those numbers are millions of real people and organizations relying on MoonPay every day. We collaborate with innovative brands and projects to build secure, scalable solutions for a blockchain-powered future. This is an opportunity to help shape systems, not just scale them. And we’re committed to doing it right. Fully licensed in the U.S. and regulated across the UK, EU, Canada, and Australia, because trust and compliance are non-negotiable.

- Conduct threat modelling reviews of Technical Design Documents (TDDs) for new and existing features, providing clear, actionable security recommendations early in the design process. - Perform and support application security assessments, including penetration testing, vulnerability assessments, and proof-of-concept (PoC) development where appropriate. - Investigate, triage, and respond to Bug Bounty program submissions, validating findings and working with engineering teams to drive timely remediation. - Own and continuously improve application-layer protections, including managing and tuning Cloudflare WAF and related security controls. - Partner closely with engineering teams to embed security best practices throughout the SDLC, from design and development through deployment and maintenance. - Research and track emerging threats and vulnerabilities, translating findings into practical mitigation strategies relevant to our technology stack. - Develop and deliver security guidance, training, and awareness for engineering teams to raise the overall security maturity of the organization. - Contribute to the creation, maintenance, and evolution of security standards, processes, and documentation. - Participate in and eventually lead incident response activities, supporting investigation, containment, remediation, and post-incident improvements.

- You have developed a breadth of experience across multiple security domains, including web and mobile application security, infrastructure and cloud security, and can connect these areas to drive a holistic security approach. - You have hands-on experience performing white-box, source code-assisted web and mobile application penetration testing, from vulnerability discovery through triage and exploitation. - You have the ability to read, understand, and review source code to identify security issues, with ideally, a particular focus on JavaScript and TypeScript codebases. - You have a strong understanding of Threat Modelling principles and their practical application to the secure software development lifecycle (SDLC). - You have experience working with web application firewalls to help protect applications, assess coverage, and support tuning rules to mitigate common attack patterns. - You have experience embedding application security practices into CI/CD pipelines, enabling early detection of vulnerabilities and close collaboration with engineering teams throughout the development lifecycle. - You have collaborated closely with engineering teams to clearly communicate security findings, explain vulnerabilities, attack paths, and mitigations, and support the implementation of effective fixes for both technical and non-technical audiences. - You are self-motivated, proactive, and take strong ownership of your work, operating effectively in a remote environment while maintaining a collaborative, team-focused mindset.

- Competitive salary ranging from $90K to $150K. - Opportunity to work remotely. - Join a team dedicated to building secure, scalable solutions for a blockchain-powered future.

MoonPay is the leading Web3 infrastructure company that onboards the world to Web3 by providing end-to-end solutions for crypto payments, enterprise-scale smart contract development, and digital asset management. They enable easy handling of crypto payments, powerful smart contracts for businesses, and digital asset management, powering Web3 experiences for iconic brands. Their engineering teams focus on areas like crypto/payments, KYC, core product, DeFi trading, on-chain asset delivery, and monetization.