Staff Application Security Engineer

OverviewStaff Application Security Engineer role at LEDN. Ledn is a global financial services company built for digital assets, helping Bitcoin holders and enabling generational wealth through egalitarian lending, savings and trading products 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. This is a hands-on engineering role with direct impact on product security, infrastructure security, and customer trust. The OpportunityYou will work across our JavaScript/TypeScript services, AWS serverless stack (Lambda, API Gateway, Cognito, SNS, SQS), MongoDB and Kubernetes microservices. You will evolve our authentication layer toward modern, phishing-resistant approaches and design and operate AWS Nitro Enclaves to protect critical data and cryptographic operations in isolated environments. ResponsibilitiesLead 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 Cognito-based identity architecture with stronger MFA (WebAuthn, passkeys, hardware tokens). Define secure approaches to session management, device trust, and account recovery. Design enclave-based architectures to isolate and protect sensitive workloads; 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. Qualifications10 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; understanding of software supply chain; deep understanding of Linux internals. Remediate vulnerabilities identified in penetration tests; strong communication and collaboration skills. Nice To HavesFamiliarity 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 FitWe seek a leader who thrives in startup or tech environments and embodies Ledn values: act with integrity, own it, have a passion for progress, and lead with empathy. The Ideal Candidate WillHave a passion for progress, adaptability, resilience, and comfort navigating ambiguity in a high-growth environment. Be a builder with enthusiasm to create, iterate, and scale IS practices. Be a collaborative partner with empathy and clarity to influence across functions and cultures. Demonstrate integrity and accountability in handling confidential information across diverse contexts. Have experience in a remote environment. A Taste Of What We ProvideGrowth opportunities within Ledn, a leading digital asset company. Comprehensive rewards package starting on day one; competitive PTO; owner equity through shared ownership. Remote-work flexibility up to 180 days worldwide (subject to restrictions). A purpose-driven career with barriers removed so you can focus on impact. Equal opportunity employer; commitment to inclusivity and diversity. OtherYou may reach out to the Ledn team for accommodation requests at any stage of the recruitment process. Requests will be addressed confidentially. Ledn is a remote-first organization with a global team across North America, Latin America, South Africa and Europe. Please note: 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; we do not accept unsolicited agency resumes. #J-18808-Ljbffr