Staff Application Security Engineer

Overview Staff Application Security Engineer at LEDN. Ledn is a global financial services company built for digital assets, offering egalitarian lending, savings and trading products to digital asset holders in over 150 countries. We are seeking a full-time engineer with deep expertise in Application Security, Identity & Access Management, and Confidential Computing to strengthen the security of our Bitcoin-backed loan platform. The Opportunity This is a hands-on engineering role with direct impact on product security, infrastructure security, and customer trust. 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 design and operate AWS Nitro Enclaves to protect critical data and cryptographic operations in isolated, verifiable environments. 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. Partner with engineers to remediate vulnerabilities and improve secure development practices. Own the roadmap for authentication and identity across customer and internal applications. Enhance existing Cognito-based identity architecture with stronger, phishing-resistant MFA solutions (e.g., WebAuthn, passkeys, hardware tokens). Collaborate with Product to align usability, compliance, and security in authentication flows. Define secure approaches to session management, device trust, and account recovery. 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. 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; develop 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 focusing 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; remediation of vulnerabilities identified in pen tests. 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). Prior work on 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. Demonstrate adaptability, resilience, and a builder's mindset to create, iterate, and scale information security practices. Be a collaborative partner who can influence across functions and cultures with empathy and clarity. Maintain integrity and accountability, especially when handling confidential information across legal and cultural contexts. Experience working in a remote environment. The Ideal Candidate Will Be passionate about progress, adaptable and resilient in a high-growth, fast-paced environment. Have a builder's mindset and enjoy creating, iterating, and scaling IS practices. Be a collaborative partner and influencer across functions and cultures. Demonstrate integrity and accountability in handling confidential information. Have prior experience working remotely. What We Provide Growth opportunities and a comprehensive total rewards package starting on day one. Competitive PTO and ownership in the company through equity shared with Ledn employees. Remote work approval up to 180 days per year (subject to restrictions). A career with purpose and a culture that removes barriers to doing great work. Ledn is an equal opportunity employer; we value inclusivity and diversity. Contact information for accommodation requests during recruitment is provided confidentially. Company Information Ledn is a globally distributed, remote-first company with teams across North America, Latin America, South Africa and Europe. Due to high application volume, 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, unsolicited resumes will not be processed. #J-18808-Ljbffr