Staff Application Security Engineer

OverviewSenior/Staff Application Security Engineer (Bangkok based, relocation provided) — Ledn is a global financial services company built for digital assets. This is a full-time role with deep expertise in Application Security, Identity & Access Management, and Confidential Computing to strengthen the security of Ledn's 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. This is a hands-on engineering position with direct impact on product security, infrastructure security, and customer trust. 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, 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 using AWS Nitro Enclaves; migrate high-value operations into enclave environments; integrate Nitro Enclaves with KMS and secure APIs; 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 Ledn10 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 the penetration test report. Strong communication and collaboration skills, able 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). Prior work on user-facing security features such as passwordless authentication, recovery flows, or device trust. Culture FitWe are looking for a leader who thrives in a startup or tech environment and embodies our values: act with integrity, own it, have a passion for progress, and lead with empathy. Demonstrate integrity and accountability, especially in managing confidential information across diverse legal and cultural contexts. Be a collaborative partner, able to influence across functions and cultures with empathy and clarity. Have worked in a remote environment before. The Ideal Candidate WillHave a passion for progress by being adaptable and resilient, and comfortable navigating ambiguity in a high-growth, fast-paced environment. Have a builder's mindset, excited to create, iterate, and scale IS practices. Be a collaborative partner across functions and cultures with empathy and clarity. Demonstrate integrity and accountability, especially in handling confidential information. Be comfortable working in a remote environment. A Taste Of What We ProvideGrowth opportunities as one of the world’s leading digital asset companies. Comprehensive total rewards package starting on day one. Competitive PTO package. Ownership in the company through shared equity. Option to work remotely anywhere in the world for up to 180 days (subject to restrictions). A role with purpose and a culture that removes barriers to doing great work. Equal opportunity employer; commitments to inclusivity and diversity. Additional NotesYou may reach out to the Ledn team with accommodation requests throughout all stages of the recruitment process. Requests will be addressed confidentially. Ledn is a remote-first, globally distributed team. Due to high volume of applications, only qualified applicants will be contacted. No agencies or recruiters, unsolicited resumes will not be considered. #J-18808-Ljbffr