Staff Application Security Engineer

OverviewStaff Application Security Engineer at LEDN.Join us to help secure the Bitcoin-backed loan platform and drive both tactical improvements and long-term strategy for securing our applications and authentication systems.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 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.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.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.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.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 seek a leader comfortable in a startup or tech environment who embodies our values: integrity, empathy, a builder's mindset, and the ability to thrive in ambiguity and fast growth.The ideal candidate will have a passion for progress, be adaptable and resilient, collaborate across functions, and maintain confidentiality across diverse legal contexts.BenefitsCompetitive total rewards package starting on your first day.Competitive PTO and remote work flexibility (up to 180 days anywhere worldwide).Company equity opportunities.Remote-first environment with a global team across North America, Latin America, South Africa, and Europe.Equal Opportunity StatementWe are an equal opportunity employment organization and pride ourselves on inclusivity, diversity, and the success that comes from diversity.Requests for accommodation throughout all stages of the recruitment process will be addressed confidentially.We do not accept unsolicited agency resumes and are not responsible for any fees related to unsolicited resumes.Recruitment ProcessOnly qualified applicants will be contacted due to high application volume.Shortlisted candidates may be asked to submit a short video response and may be asked to provide publicly available social media activity relevant to the role.No agencies or recruiters please.#J-*****-Ljbffr