Security Engineer

OverviewSecurity Engineer at LEDN is a full-time role focused on strengthening the security of Ledn’s Bitcoin-backed loan platform. 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. We offer a suite of egalitarian lending, savings and trading products to digital asset holders in over 150 countries. The role drives both tactical improvements and long-term strategy for securing applications and authentication systems, and involves working across JavaScript/TypeScript services, AWS serverless stack, MongoDB and Kubernetes microservices, with ownership of evolving the authentication layer toward modern, phishing-resistant approaches. The role also includes designing and operating AWS Nitro Enclaves to protect critical data and cryptographic operations in isolated, verifiable environments. This is a hands-on engineering position with direct impact on product security, infrastructure security, and customer trust. Responsibilities Application Security: 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; partner with engineers to remediate vulnerabilities and improve secure development practices. Authentication & Identity: Own the roadmap for authentication and identity across customer and internal applications; enhance Cognito-based identity architecture with stronger, phishing-resistant 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. Confidential Computing (AWS Nitro Enclaves): Design enclave-based architectures to isolate and protect sensitive workloads; integrate Nitro Enclaves with KMS and secure APIs; migrate high-value operations into enclave environments; ensure compliance, auditability, and resilience of enclave workloads. Additional Security Domains: Harden AWS services 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; develop detection rules, dashboards, and incident playbooks; support compliance initiatives (SOC 2, ISO 27001). What You Bring To Ledn 10+ years 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; understanding of software supply chain; deep understanding of Linux internals. Remediate vulnerabilities identified in penetration test reports; strong communication and collaboration skills, capable of influencing engineering and product teams. Nice To Haves Familiarity with Bitcoin custody and key management practices. Knowledge of Infrastructure as Code security (Terraform, AWS CDK). Prior work on user-facing security features such as passwordless authentication, recovery flows, or device trust. Culture & Benefits We’re looking for a leader who thrives in a startup or tech environment and embodies our values: act with integrity, own it, have a passion for progress, and lead with empathy. Ledn offers a comprehensive total rewards package, generous PTO, and ownership through equity. We support remote work worldwide for up to 180 days (subject to restrictions). Ledn is an equal opportunity employer and values diversity and inclusion. We provide accommodations requests confidentially at any stage of the recruitment process. Equal Opportunities Ledn is an equal opportunity employment organization and prides itself on inclusivity, diversity, and the success that comes from diversity. How to Apply To apply for the Security Engineer role at LEDN, please submit your resume and details through the application process. #J-18808-Ljbffr