Staff Application Security Engineer

Staff Application Security EngineerLEDN is a global financial services company focused on digital assets, offering 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.The OpportunityThis hands-on engineering role drives both tactical improvements and long-term strategy for securing our applications and authentication systems.You'll work across JavaScript/TypeScript services, AWS serverless stack (Lambda, API Gateway, Cognito, SNS, SQS), MongoDB, Kubernetes microservices, and own the evolution of our authentication layer toward modern, phishing-resistant approaches.Additionally, you will design and operate AWS Nitro Enclaves to protect critical data and cryptographic operations in isolated, verifiable environments.Application SecurityLead 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 & IdentityOwn the roadmap for authentication and identity across customer and internal applications.Enhance existing Cognito-based identity architecture with stronger, phishing-resistant MFA solutions (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.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 (cryptographic and financial processes) into enclave environments.Ensure compliance, auditability, and resilience of enclave workloads.Additional Security DomainsHarden 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 *****) with security controls and documentation.What You Bring To Ledn10+ years of proven experience in Application Security focused 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 software supply-chain security.Deep understanding of Linux internals.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 FitAdaptable, resilient, and comfortable navigating ambiguity in a high-growth, fast-paced environment.Builder's mindset, excited to create, iterate, and scale IS practices.Collaborative partner with empathy and clarity, influencing across functions and cultures.Integrity and accountability, especially in managing confidential information across diverse legal and cultural contexts.Experience working remotely.BenefitsCompetitive PTO package and flexible remote work policy (up to 180 days worldwide).Ownership opportunities and shared equity.Comprehensive, best-in-class total rewards package starting on your first day.Equal opportunity employment organization, proud of inclusivity, diversity, and success from diversity.Requests for reasonable accommodations will be addressed confidentially.#J-*****-Ljbffr