Senior Application Security Engineer

About the role

In this role, you will be responsible for conducting threat modeling reviews and performing application security assessments, including penetration testing and vulnerability assessments. You will partner with engineering teams to embed security best practices throughout the development lifecycle, ensuring that security is prioritized from design to deployment.

You will also manage application-layer protections, investigate Bug Bounty submissions, and develop security guidance for engineering teams. Your work will directly contribute to improving the security maturity of the organization and shaping secure systems that support MoonPay's mission of driving mainstream crypto adoption.

The salary for this position ranges from $90,000 to $150,000, reflecting the seniority and expertise required.

Skills that matter here

• application security: This role requires a breadth of experience in application security to protect digital transactions.
• penetration testing: You will perform penetration testing to identify and address vulnerabilities in applications.
• vulnerability assessments: Conducting vulnerability assessments is a key responsibility to ensure system integrity.
• cloud security: A strong understanding of cloud security is necessary to manage application-layer protections.
• JavaScript: You will review and analyze JavaScript codebases to identify security issues.
• TypeScript: Experience with TypeScript is important for assessing and securing code in this environment.

Who this role suits

• A candidate who is proactive and self-motivated, thriving in a remote work environment.
• Someone with a collaborative mindset, capable of communicating complex security findings to technical and non-technical audiences.
• An individual with a strong ownership mentality, taking responsibility for their work and contributing to team goals.
• A person who has developed diverse experience across multiple security domains, enhancing a holistic security approach.

From the employer

• 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.