Staff Application Security Engineer

OverviewJoin to apply for the Staff Application Security Engineer role at LEDN . LEDN is a global financial services company built for digital assets, helping to improve the everyday lives of Bitcoin holders while building generational wealth for the future. We offer a suite of egalitarian lending, savings and trading products to digital asset holders in over 150 countries. Our team is committed to democratizing access to the global economy and Ledn’s products and services play a critical role in that effort. About Ledn: Ledn is a remote-first, global company with a diverse team. We value integrity, ownership, progress, and empathy. The OpportunityWe 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 our customers and business, and this role will drive both tactical improvements and long-term strategy for securing our applications and authentication systems. 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, 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. 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. What You Bring To Ledn 10 years minimum of proven experience in Application Security focusing 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. 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 value leadership, adaptability, and resilience in a high-growth, fast-paced environment. Builder's mindset to create, iterate, and scale IS practices. Collaborative partner, able to influence across functions and cultures with empathy and clarity. Integrity and accountability in managing confidential information across diverse contexts. Experience in a remote environment. What We Provide Competitive total rewards package starting on day one. Generous PTO and remote work flexibility (up to 180 days remote, subject to restrictions). Equity ownership in the company. Remote-friendly environment with global opportunities. A purpose-driven career that aims to remove barriers and empower employees. We are an equal opportunity employer and value diversity. You may reach out to the Ledn team for accommodation requests during all stages of the recruitment process. Requests will be handled confidentially. Ledn Working Environment: Ledn is truly global and remote-first. Please note that due to high volume of applications, 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 please. We do not accept unsolicited agency resumes and are not responsible for fees related to unsolicited resumes. Job Details Seniority level: Mid-Senior level Employment type: Full-time Job function: Information Technology Industries: Retail Contagem, Minas Gerais, Brazil #J-18808-Ljbffr