Senior Application Security Engineer

Overview

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Rain is the fastest-growing earned wage access (EWA) fintech in the U.S., serving 3.5 million employees and backed by top investors like QED and Prosus. We have raised nearly $400M in funding—including the largest Series A in fintech history—and recently closed our Series B to fuel our next stage of hypergrowth.

This role is focused on secure software development and cloud-native defense. You will partner closely with engineering and development squads and work with our Cloud Security and GRC teams to improve Rain\'s application and platform security posture. It is technically grounded, requiring direct engagement in application-layer matters and security reviews while contributing to cloud security automation, awareness initiatives, and secure engineering practices across the SDLC.

• Collaborate with development squads to validate vulnerabilities and provide actionable remediation guidance aligned with business risk.
• Drive threat modeling sessions (e.g., STRIDE, PASTA) for critical systems and APIs.
• Design, implement, and oversee automated processes for securely updating application and code dependencies, proactively mitigating issues and ensuring timely vulnerability remediation.
• Integrate security checks into CI/CD pipelines (SAST, DAST, SCA, IaC), using tools like Semgrep, Snyk, Trivy, and Burp Suite.
• Contribute to runtime security initiatives, including container/Kubernetes hardening, RASP, and eBPF-based detection.
• Build and maintain a security issues dashboard to track remediation status and metrics.
• Provide real-time support during cybersecurity incidents impacting applications or cloud infrastructure (e.g., exploited vulnerabilities, credential stuffing, web/API attacks).
• Partner with the Cloud Security team on security automation tasks and monitoring improvements (e.g., Security Hub remediation automations, DLP monitoring).
• Conduct proactive research on new threats, vulnerabilities, and attack techniques relevant to Rain\'s architecture.
• Collaborate with the GRC team to develop and deliver internal security awareness initiatives, phishing campaigns, and developer training (e.g., secure coding, API security).
• Participate in continuous improvement of AppSec maturity (e.g., OWASP SAMM, ISO 27001, SOC 2 frameworks).

• Fluent English with strong verbal and written skills; excellent communication to convey security risks to technical and non-technical stakeholders.
• 3–5+ years of experience in application security, penetration testing, or secure code development, including work with QA teams.
• Hands-on experience with SAST, DAST, and SCA tools (e.g., Semgrep, Burp, Snyk).
• Deep understanding of web, mobile, and API vulnerabilities (OWASP Top 10, API Top 10, MITRE CWE).
• Proficiency in at least one backend language (e.g., Go, Python, Node.js) and understanding of React/React Native front-ends.
• Familiarity with secure architecture of microservices, event-driven systems, and REST APIs using OAuth2/OpenID Connect.
• Experience securing CI/CD pipelines and integrating AppSec tooling into SDLC.
• Solid knowledge of containerization and Kubernetes security fundamentals.
• Understanding of cloud security (preferably AWS), including IAM, cloud-native service configurations, and network segmentation.
• Comfort with Agile development methodologies and cross-functional squads.
• Software supply chain security (e.g., SBOM, artifact signing).

• Certifications such as OSCP, OSWE, GWAPT, CPTE, or CSSLP.
• AWS, GCP, or Azure Security Specialty certification.
• Familiarity with bug bounty triage and vulnerability management platforms (e.g., DefectDojo).
• Experience implementing RASP or eBPF runtime protection tools.
• Exposure to LLM/AI security considerations and secure code generation practices.
• Familiarity with logging and monitoring tools (e.g., CloudWatch, Datadog, Grafana).

Rain is a diverse, mission-driven team that values growth and adaptability. We are committed to Equal Employment Opportunity and do not discriminate based on race, religion, color, national origin, ethnicity, gender, sex (including pregnancy), protected veteran status, age, disability, sexual orientation, gender identity, or gender expression. If you need assistance or accommodation due to a disability, you may contact us at ******.