Senior Application Security Engineer

Senior Application Security Engineer role at Rain.

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 just closed our Series B. This role is on Rain's Security team, focusing on secure software development and cloud-native defense.

You will partner closely with engineering, Cloud Security, and GRC teams to improve Rain's application and platform security posture. The role is technically grounded, involving application-layer security reviews and security automation 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, 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 (container/Kubernetes hardening, RASP, 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.
• Partner with the Cloud Security team on security automation tasks and monitoring improvements (e.g., Security Hub 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 and developer training (secure coding, API security).
• Participate in the continuous improvement of AppSec maturity (e.g., OWASP SAMM, ISO 27001, SOC 2).

• Fluent English, including strong verbal and written skills.
• Strong problem-solving and analytical mindset.
• Excellent communication skills to convey security risks to technical and non-technical stakeholders.
• 3–5+ years of experience in application security, penetration testing, and/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).
• Proven expertise in performing code reviews or security assessments and writing clear reports.
• 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 the SDLC.
• Solid knowledge of containerization and Kubernetes security fundamentals.
• Understanding of cloud security (preferably AWS), including IAM principles, cloud-native service configurations, and network segmentation.
• Comfortable 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 team united by a mission-driven culture. We own what we do and let data guide our actions while working quickly and adapting to new challenges every day. Rain is committed to Equal Employment Opportunity and does not discriminate based on race, religion, color, national origin, ethnicity, gender, sex (including pregnancy), protected veteran status, age, disability, sexual orientation, gender identity, gender expression, or any unlawful criterion under applicable laws. If you need assistance or accommodations due to a disability, you may contact us at ******.

• Seniority level: Mid-Senior level
• Employment type: Full-time
• Job function: Information Technology

Referrals increase your chances of interviewing at Rain. Get notified about new Senior Application Security Engineer jobs in Caxias do Sul, Rio Grande do Sul, Brazil.