Staff Application Security Engineer

OverviewStaff 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.Ledn offers a suite of egalitarian lending, savings and trading products to digital asset holders in over 150 countries.The core values are act with integrity, ownership, passion for progress, and empathy.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.This is a hands-on engineering role with direct impact on product security, infrastructure security, and customer trust.Security is fundamental to protecting our customers and business.This role will drive tactical improvements and long-term strategy for securing our applications and authentication systems.You will work across our JavaScript/TypeScript services, AWS serverless stack (Lambda, API Gateway, Cognito, SNS, SQS), MongoDB and Kubernetes microservices, and take ownership of evolving our authentication layer toward modern, phishing-resistant approaches.You will design and operate AWS Nitro Enclaves to protect critical data and cryptographic operations in isolated, verifiable environments.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 (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 with KMS and secure APIs.Migrate high-value operations into enclave environments; 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 *****) 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; understanding of software supply chain; strong Linux internals knowledge.Remediate vulnerabilities identified in penetration tests; strong communication and collaboration skills to influence across teams.Nice to HaveFamiliarity with Bitcoin custody and key management practices.Knowledge of Infrastructure as Code security (Terraform, AWS CDK).Prior work on user-facing security features (passwordless authentication, recovery flows, device trust).Culture & GrowthWe look for leaders who thrive in startup or tech environments and embody our values.The ideal candidate will be adaptable, resilient, a builder, collaborative, and capable of navigating ambiguity in a high-growth setting.We value integrity, accountability, and a remote-friendly, inclusive culture.What We ProvideComprehensive, best-in-class total rewards package, with ownership through equity and the opportunity to work remotely up to 180 days per year (restrictions apply).A career with purpose and the chance to be part of a global digital asset company.You may reach out for accommodation requests throughout all stages of the recruitment process.Ledn is an equal opportunity employer and promotes inclusivity.We do not accept unsolicited agency resumes.Location & ContactWe are remote-first with global teams; the role references Recife, Pernambuco, Brazil for job postings and notifications.#J-*****-Ljbffr