Senior Application Security Engineer

MoonPay

$120K — $150K *
US-AnywhereRemote in Canada
Information Technology
Less than 5 years of experience
Job Overview by Ladders

Qualifications

  • 5-7 years of experience in application and cloud security fields.
  • Hands-on experience with web/mobile application penetration testing.
  • Proficient in reading and reviewing source code, especially in JavaScript and TypeScript.
  • Strong understanding of threat modeling principles in the SDLC.
  • Experience managing web application firewalls and security controls.
  • Familiarity with CI/CD pipelines and embedding security practices.
  • Excellent collaboration and communication skills with technical and non-technical teams.

Responsibilities

  • Conduct threat modeling for new/existing features, offering actionable recommendations.
  • Perform application security assessments and penetration testing.
  • Manage Bug Bounty submissions, validating and facilitating timely remediation.
  • Enhance application-layer protections using Cloudflare WAF.
  • Embed security best practices in the software development lifecycle with engineering teams.
  • Research emerging threats and create practical mitigation strategies.
  • Develop and deliver security training to engineering teams.
  • Contribute to the maintenance of security standards and incident response activities.

Benefits

  • Competitive salary package.
  • Equity package for employee ownership.
  • Performance-based equity bonus for exceptional contributors.
  • Unlimited holidays for flexible work-life balance.
  • Fully remote or hybrid working options available.
  • Private healthcare benefits for you and your family.
  • Enhanced parental leave.
  • Annual training budget to support professional growth.
  • Home office setup allowance for your workspace.
  • Remote working allowance for utility support.
  • Monthly budget for product purchases and zero fee crypto transactions.
  • Employee referral program with financial incentives.
  • Regular remote company offsites for team bonding.
Full Job Description
Locations Supported
  • US
  • Canada (Toronto)
  • Mexico

Relocation available:No

Work pattern:
  • This role will be remote.


About the Opportunity

👉 Write a clear, high-level overview of the role, outlining its purpose, scope, and impact on the team and wider organisation.

Our SRE/Cloud Security teams are a dynamic blend of proactive defenders and inquisitive problem-solvers. We are dedicated to strengthening our systems through rigorous security reviews and hands-on penetration testing, and we actively manage our Bug Bounty program to ensure timely validation, response, and remediation.

We leverage cutting-edge tools and techniques to build robust defenses, and collaboration is central to how we work; embedding security best practices throughout the SDLC. We continuously research emerging threats, develop effective mitigation strategies, and empower engineering teams through clear guidance and practical security training.

We maintain up-to-date security standards and documentation, lead incident response efforts with precision, and are passionate about spreading a secure-by-design culture while contributing to the wider security community.

What You Will Do

👉 A concise and detailed breakdown of core responsibilities, day-to-day expectations, and key deliverables. Use 5-10 bullets max.
  • 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.


About You

👉 Describe the ideal candidate's qualifications, skills, experience, and behaviours that show strong culture alignment.

Must-have experience and skills
  • 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.

Nice-to-have experience
  • You have experience in JavaScript and TypeScript, including the ability to read, understand, and reason about modern web application codebases.
  • You have experience working with Cloudflare, including its hosting and Web Application Firewall (WAF) capabilities, to help secure and operate internet-facing applications.
  • You have experience testing and securing GraphQL, REST APIs, including understanding common GraphQL/REST-specific attack vectors and security considerations.
  • You have experience or a strong interest in Web3 security testing, including assessing smart contracts, blockchain-based applications, or Web3 integrations.
  • You have an interest in agentic engineering, including emerging patterns in autonomous systems, tooling, or workflows, and their security implications.


Bonus Points

👉 Optional extras that would help a candidate stand out (keep this short).
  • You contribute or have contributed to the security community through open source involvement, participation in CTFs, or speaking at local information security meetups and conferences.
  • Your background includes experience working with disruptive technologies and successfully launching products, ideally within FinTech, SaaS, or Crypto.
  • You hold one or more security relevant certifications such as OSCP or OSWE.


BLOCK Values

We're looking for people who live our core values, those who strive for excellence and want to leave a lasting legacy on the global financial system. Our values:

B - Be Hungry

L - Level Up

O - Own It

C - Crypto Curious

K - Kaizen

Research has shown that women are less likely than men to apply for this role if they do not have experience in 100% of these areas. Please know that this list is indicative, and that we would still love to hear from you even if you feel that you are only a 75% match. Skills can be learnt, diversity cannot.

Benefits & Perks

Competitive salary package

Equity package: We believe financial freedom starts with our employees, so all employees have ownership at MoonPay

Pay for performance equity bonus: Those who drive outsized outcomes receive outsized rewards

Moonshot award. We honor exceptional impact - 10 employees twice a year, each earning a $250,000 equity grant.

Unlimited holidays: We give you the autonomy to choose when to work (and when to switch off)

Hybrid working schedule: Work fully remotely or your nearest Moonbase, the choice is yours

🩺 Private Healthcare benefits: To protect you and your loved ones

🍼 Enhanced parental leave: So you can spend more time with your loved ones without a second thought

Annual training budget: We support your training journey every step of the way

🪑 Home office setup allowance: Create the home office of your dreams

👛 Remote working allowance: Those working fully remotely get a little extra for utilities

Monthly budget to spend on our products and zero fee crypto transactions: Cultivate your inner DEGEN

Employee referral programme: Great people know great people, refer them to receive 10K in USDC

Regular remote company offsites: Meet your colleagues regularly for high impact in person sessions and hackathons

Working in a disruptive and fast-growing company where excellence is rewarded

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