Staff Application Security Engineer

Overview Ledn is a global financial services company building for digital assets. We offer lending, savings and trading products to digital asset holders in over 150 countries. We are seeking a full-time Staff Application 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 is fundamental to protecting our customers and business, and this role will drive both tactical improvements and long-term strategy for securing our applications and authentication systems. You will work across our JavaScript/TypeScript services, AWS serverless stack (Lambda, API Gateway, Cognito, SNS, SQS), MongoDB and Kubernetes microservices, and take ownership of evolving our authentication layer toward modern, phishing-resistant approaches. You will also design and operate AWS Nitro Enclaves to protect critical data and cryptographic operations in isolated, verifiable environments. This is a hands-on engineering role with direct impact on product security, infrastructure security, and customer trust. We value integrity, ownership, progress, and empathy, and seek team members who share these principles as we build and innovate in the financial services space. 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 architectures with stronger, phishing-resistant MFA solutions (e.g., 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; integrate 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); deploy and operate a SIEM framework and develop detection rules, dashboards, and incident playbooks. Support compliance initiatives (SOC 2, ISO 27001) with security controls and documentation. Qualifications Minimum 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, especially in serverless architectures; hands-on AWS Nitro Enclaves experience. 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 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 on user-facing security features such as passwordless authentication, recovery flows, or device trust. Culture & Benefits Remote-first environment with opportunities to work remotely globally (subject to restrictions). Comprehensive total rewards package, PTO, and ownership in the company via equity. Opportunity to contribute to a leading digital asset company and a mission-driven team. Support for accommodation requests and an inclusive, diverse workplace. We are an equal opportunity employment organization and pride ourselves on inclusivity, diversity, and the success that comes from diversity. You may reach out to the Ledn team for accommodation requests at any stage of the recruitment process. Requests will be addressed confidentially. #J-18808-Ljbffr