Security Engineer

Overview Security Engineer at LEDN. Ledn is a global financial services company built for digital assets, helping to improve the everyday lives of Bitcoin holders while building generational wealth for the future. LEDN offers egalitarian lending, savings and trading products to digital asset holders in over 150 countries. Our team is diverse and focused on using digital assets to democratize access to the global economy. The Opportunity We are seeking a full-time Security Engineer with deep expertise in Application Security, Identity & Access Management, and Confidential Computing to strengthen the security of our Bitcoin-backed loan platform. Security drives both tactical improvements and long-term strategy for securing applications and authentication systems. You will work across JavaScript/TypeScript services, AWS serverless stack (Lambda, API Gateway, Cognito, SNS, SQS), MongoDB and Kubernetes microservices, and will evolve our authentication layer toward modern, phishing-resistant approaches. You will design and operate AWS Nitro Enclaves to protect critical data and cryptographic operations in isolated environments. This is a hands-on engineering role with direct impact on product security, infrastructure security, and customer trust. Responsibilities 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 in collaboration with engineers. Own the roadmap for authentication and identity across customer and internal applications. Enhance Cognito-based identity with MFA solutions (WebAuthn, passkeys, hardware tokens). Define secure session management, device trust, and account recovery approaches. Design enclave-based architectures to isolate and protect sensitive workloads using AWS Nitro Enclaves, integrating with KMS and secure APIs. Migrate high-value operations into enclave environments and ensure compliance, auditability, and resilience. 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). Practical 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. Deep understanding of Linux internals and remediation of vulnerabilities identified in penetration testing. 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 We seek a leader who thrives in startup or tech environments and embodies our values: act with integrity, own it, have a passion for progress, and lead with empathy. Be adaptable, resilient, and comfortable navigating ambiguity in a high-growth, fast-paced environment. Have a builder's mindset and enjoy creating, iterating, and scaling information security practices. Be a collaborative partner across functions and cultures with empathy and clarity; manage confidential information responsibly. Experience working in a remote environment. A Taste Of What We Provide Growth opportunities as LEDN is a leading digital asset company. Comprehensive rewards package, PTO, and ownership in the company via equity. Remote work flexibility up to 180 days globally (subject to restrictions). A purpose-driven career and inclusive, diverse environment. Other notes LEDN is an equal opportunity employer; we value inclusivity and diversity. Contact for accommodation requests at any stage of recruitment, with confidential handling. Our team is global and remote-first; applications may be screened with video responses and social media review where relevant. Notes Seniority level: Mid-Senior level Employment type: Full-time Job function: Information Technology Industries: Retail J-18808-Ljbffr

Location: Duque de Caxias, Rio de Janeiro, BR

Posted Date: 10/13/2025