Security Engineer

Overview Security Engineer with deep expertise in Application Security, Identity & Access Management, and Confidential Computing to strengthen the security of Ledn's Bitcoin-backed loan platform. This is a hands-on engineering role with direct impact on product security, infrastructure security, and customer trust. What You Will Do Lead secure design and code reviews across engineering teams. Define and enforce secure coding practices for JavaScript/TypeScript services. Automate vulnerability detection (SAST, SCA, DAST) within CI/CD. Conduct threat modeling and risk assessments for new features. Remediate vulnerabilities and improve secure development practices with engineers. Own the roadmap for authentication and identity across customer and internal applications. Enhance Cognito-based identity architecture with stronger MFA solutions (WebAuthn, passkeys, hardware tokens). Collaborate with Product to align usability, compliance, and security in authentication flows. Define secure session management, device trust, and account recovery approaches. Design enclave-based architectures to isolate and protect sensitive workloads using AWS Nitro Enclaves. Integrate Nitro Enclaves with KMS and secure APIs; migrate high-value operations into enclave environments. Harden AWS services (Lambda, API Gateway, SQS, SNS) with least-privilege IAM and secure key management. Improve Kubernetes security posture (RBAC, pod security, image scanning, runtime monitoring). Deploy and operate a SIEM framework with detection rules, dashboards, and incident playbooks. Support compliance initiatives (SOC 2, ISO 27001) with security controls and documentation. What You Bring To Ledn 10 years minimum of proven experience in Application Security with a focus on web and cloud-native applications. Strong knowledge of JavaScript/TypeScript/Golang/Python and modern web vulnerabilities (OWASP Top 10, auth bypasses, business logic flaws). Expertise with AWS security best practices, particularly in serverless architectures. Hands-on experience with AWS Nitro Enclaves for confidential computing. Deep understanding of authentication and authorization standards (OAuth2, OIDC, WebAuthn, FIDO2). Experience with Cognito / Auth0 (MFA, custom flows, secure session handling). Background in SIEM design and log correlation across cloud and application layers. Familiarity with Kubernetes security (RBAC, pod security, admission controls, image scanning). Experience with Secure Code Review and understanding of software supply chain. Strong communication and collaboration skills to influence engineering and product teams. Nice To Haves Familiarity with Bitcoin custody and key management practices. Knowledge of Infrastructure as Code security (Terraform, AWS CDK). Experience with user-facing security features such as passwordless authentication, recovery flows, or device trust. Culture Fit & The Ideal Candidate Lead with adaptability, resilience, and the ability to navigate ambiguity in a high-growth, fast-paced environment. Builder mindset: create, iterate, and scale information security practices. Collaborative, able to influence across functions and cultures with empathy and clarity. Integrity and accountability in handling confidential information across diverse contexts. Experience working in a remote environment. What We Provide Comprehensive total rewards package starting on day one. Competitive PTO and ownership in the company via equity. Remote-friendly policy, with the ability to work remotely from anywhere in the world for up to 180 days (subject to restrictions). Purposeful work in a leading digital asset company. Inclusive, diverse, equal opportunity employer; accommodations available throughout recruitment. Ledn is remote-first and globally distributed across North America, Latin America, South Africa and Europe. Note: due to high volume of applications, only qualified applicants will be contacted. Shortlisted candidates may be asked to submit a short video response, and we may review publicly available social media activity relevant to the role. No agencies or recruiters please. We do not accept unsolicited agency resumes and are not responsible for fees related to them. Seniority level: Mid-Senior level Employment type: Full-time Job function: Information Technology Industries: Retail J-18808-Ljbffr

Location: Mauá, São Paulo, BR

Posted Date: 10/13/2025