Senior Application Security Engineer

Sierra Ventures; Miami (FL); Hybrid; USD 140,000 - 200,000; Full time

Benefits offered by this job

Competitive starting pay

Discretionary annual bonus

Long-term equity incentive grants

Comprehensive health plans

401K with company matching

Paid parental leave

Flexible time off

Job summary

Gemini is seeking a Senior Application Security Engineer to partner with engineering, product and business teams to embed security judgment into product design and delivery. You will lead secure design reviews, threat modeling, code reviews and penetration testing for high‑risk products such as crypto custody, trading systems and payments.

You will build AppSec tooling, including AI agents for secure design and code review, and will drive secure coding practices across cross‑functional teams,

Qualifications

• 5+ years of experience in application security or similar roles.
• Ability to perform design reviews, threat modeling, secure code reviews, or penetration testing with an attacker mindset.
• Experience building or meaningfully contributing to security tooling and automation.
• Strong background in application security best practices and familiarity with common vulnerabilities (e.g. SSRF, race conditions, privilege escalations).
• Some background in development or scripting experience (Python, Scala, C++, or JavaScript) with the ability to read and write code.
• Strong communication skills to influence without authority and the ability to collaborate on a cross‑functional team with competing priorities.

Responsibilities

• Lead secure design reviews, threat modeling, code review, and penetration testing for high‑risk products such as crypto custody, trading systems, and payments
• Build and ship code: design and build AppSec tooling including AI agents for secure design and code review, AI‑enhanced SAST/DAST pipelines, and automation that eliminates repeatable security toil
• Partner with engineering teams to remediate vulnerabilities and drive long‑term improvements in secure coding practices

Skills

5+ years in App Security

Threat modeling & design reviews

Security tooling & automation

Secure coding practices & vulns

Scripting languages (Python/Scala/C/C+

Job description

Senior Application Security Engineer

As a Senior Application Security Engineer on the Application Security team, you will be a trusted partner to engineering, product, and business teams across Gemini. You will help guide teams to design and build secure products while building systems and culture that embed security judgment into every team. Gemini is AI‑first and AppSec builds the tools to make this vision secure.

Responsibilities

• Lead secure design reviews, threat modeling, code review, and penetration testing for high‑risk products such as crypto custody, trading systems, and payments
• Build and ship code: design and build AppSec tooling including AI agents for secure design and code review, AI‑enhanced SAST/DAST pipelines, and automation that eliminates repeatable security toil
• Partner with engineering teams to remediate vulnerabilities and drive long‑term improvements in secure coding practices

Minimum Qualifications

• 5+ years of experience in application security or similar roles
• Ability to perform design reviews, threat modeling, secure code reviews, or penetration testing with an attacker mindset
• Experience building or meaningfully contributing to security tooling and automation
• Strong background in application security best practices and familiarity with common vulnerabilities (e.g. SSRF, race conditions, privilege escalations, etc.)
• Some background in development or scripting experience (Python, Scala, C++, or JavaScript) with the ability to read and write code
• Strong communication skills to influence without authority and the ability to collaborate on a cross‑functional team with competing priorities

Preferred Qualifications

• Experience building AI application security tooling using agents or skills
• Experience with supply chain security, common frameworks (SLSA, OWASP SPVS) and other CI/CD security controls
• Familiarity with highly regulated environments (financial services, fintech, crypto, or equivalent) and ability to understand business objectives, business context, and security risk
• Experience with preventing application security vulnerabilities at scale through secure design patterns, automated tooling, or frameworks
• Experience with microservice architectures and cloud‑native environments

Benefits

• Competitive starting pay
• A discretionary annual bonus
• Long‑term incentive in the form of a new hire equity grant
• Comprehensive health plans
• 401K with company matching
• Paid parental leave
• Flexible time off

Salary Range

The base salary range for this role is between $140,000 - $200,000 in the State of New York, the State of California and the State of Washington. This range is not inclusive of our discretionary bonus or equity package. When determining a candidate’s compensation, we consider a number of factors including skillset, experience, job scope, and current market data.

Work Environment

In the United States, we offer a hybrid work approach at our hub offices, balancing the benefits of in‑person collaboration with the flexibility of remote work. Expectations may vary by location and role, so candidates are encouraged to connect with their recruiter to learn more about the specific policy for the role. Employees who do not live near one of our hubs are part of our remote workforce.

At Gemini, we strive to build diverse teams that reflect the people we want to empower through our products, and we are committed to equal employment opportunity regardless of race, color, ancestry, religion, sex, national origin, sexual orientation, age, citizenship, marital status, disability, gender identity or Veteran status. Equal Opportunity is the Law, and Gemini is proud to be an equal opportunity workplace. If you have a specific need that requires accommodation, please let a member of the People Team know.