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 building generational wealth. Ledn offers egalitarian lending, savings and trading products to digital asset holders in over 150 countries. The team values integrity, accountability, progress, and empathy, and Ledn supports remote work and global collaboration. The Opportunity: 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 customers and the business, and this role will drive tactical improvements and long-term strategy for securing applications and authentication systems. You will work across JavaScript/TypeScript services, AWS serverless stack (Lambda, API Gateway, Cognito, SNS, SQS), MongoDB and Kubernetes microservices, and evolve 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 environments. This is a hands-on engineering role with direct impact on product security, infrastructure security, and customer trust. ResponsibilitiesApplication 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 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; Deploy and operate a SIEM framework; 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 and understanding of software supply chain. Deep understanding of Linux internals; remediation of vulnerabilities identified in penetration tests. Strong communication and collaboration skills to influence engineering and product teams. Nice To HavesFamiliarity with Bitcoin custody and key management practices. Knowledge of Infrastructure as Code security (Terraform, AWS CDK). Experience with user-facing security features such as passwordless authentication, recovery flows, or device trust. Culture FitSeeking a leader who thrives in a startup or tech environment and embodies LEDN’s values of integrity, ownership, progress, and empathy. The Ideal Candidate WillBe adaptable, resilient, and comfortable navigating ambiguity in a high-growth environment. Have a builder’s mindset to create, iterate, and scale IS practices. Be a collaborative partner and influence across functions with empathy and clarity. Demonstrate integrity and accountability, especially in handling confidential information across legal and cultural contexts. Have worked in a remote environment before. What We ProvideGrowth opportunities and a comprehensive rewards package starting on day one. Competitive PTO and ownership in the company through equity. Remote-work eligibility for up to 180 days worldwide (subject to restrictions). A role with purpose and a culture that removes barriers to doing great work. Equal opportunity employer; we value inclusivity and diversity. Notes: You may reach out to Ledn for accommodation requests throughout all stages of the recruitment process. Requests will be addressed confidentially. Ledn is a remote-first, globally distributed company. 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 are not accepted. Senior/Staff Application Security Engineer (Bangkok based, relocation provided)Senior Application Security Engineer (Bangkok based, relocation provided)We’re unlocking community knowledge in a new way. Experts add insights directly into each article, started with the help of AI. #J-18808-Ljbffr