Staff Application Security Engineer

Overview Staff Application Security Engineer role at LEDN. Ledn is a global financial services company built for digital assets, offering lending, savings and trading products to digital asset holders in over 150 countries. The role focuses on Application Security, Identity & Access Management, and Confidential Computing to strengthen the security of Ledn's Bitcoin-backed loan platform. This is a hands-on engineering role with direct impact on product security, infrastructure security, and customer trust. Role involves working across JavaScript/TypeScript services, AWS serverless stack, MongoDB and Kubernetes microservices, and evolving the authentication layer toward modern, phishing-resistant approaches. The role includes designing and operating 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 Cognito-based identity architecture with stronger 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 using AWS Nitro Enclaves. Integrate Nitro Enclaves 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, 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. Qualifications 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. Remediate vulnerabilities identified in penetration test reports. Strong communication and collaboration skills, able 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’re looking for a leader who thrives in startup or tech environments and embodies our values: integrity, progress, empathy, and accountability. Demonstrate adaptability, resilience, and the ability to navigate ambiguity in a high-growth, fast-paced environment. Have a builder’s mindset and be excited to create, iterate, and scale information security practices. Be a collaborative partner able to influence across functions and cultures with empathy and clarity. Have experience working in a remote environment. A Taste Of What We Provide Comprehensive, best-in-class total rewards package starting on day one. Competitive PTO and remote-friendly work options (up to 180 days remote per year, subject to restrictions). Ownership in the company through equity participation. Remote-friendly environment with global reach. A purpose-driven role with barriers removed so you love what you do. Equal opportunity employer; Ledn values inclusivity and diversity. Accommodation requests can be emailed confidentially at any stage of the recruitment process. Ledn Working Environment: Our team is global and remote-first across North America, Latin America, South Africa and Europe. Please note, due to high volume of applications, only qualified applicants will be contacted. Shortlisted candidates may be asked to submit a short video response and our review may include publicly available social media activity relevant to the role. No agencies or recruiters, and Ledn is not responsible for fees related to unsolicited resumes. #J-18808-Ljbffr