Security Engineer

Security Engineers, Ledn is interested in hearing from you 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. Through our products & services, we can make a difference in the lives and futures of our clients in real terms. Our team at Ledn is a passionate group of individuals from diverse backgrounds united by a conviction that digital assets can democratize access to the global economy. Opportunity We are seeking a full‑time 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. You will work across our JavaScript/TypeScript services, AWS serverless stack (Lambda, API Gateway, Cognito, SNS, SQS), MongoDB and Kubernetes microservices, taking ownership of evolving our authentication layer toward modern, phishing‑resistant approaches, and designing and operating AWS Nitro Enclaves to protect critical data and cryptographic operations in isolated, verifiable environments. 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 pipelines. 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 (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. Integrate Nitro Enclaves with KMS and secure APIs. Migrate high‑value operations (e.g., 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 27001) with security controls and documentation. Qualifications 10+ 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. Understanding of software supply chain security. Deep understanding of Linux internals. Remediate vulnerabilities identified in penetration test reports. 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 Passion for progress, adaptability, resilience, and embracing ambiguity in a high‑growth, fast‑paced environment. Builder’s mindset, excited to create, iterate, and scale information‑security practices. Collaborative partner, able to influence across functions and cultures with empathy and clarity. Demonstrate integrity and accountability, especially in managing confidential information across diverse legal and cultural contexts. Experience working remotely and in a distributed environment. Benefits and Perks Comprehensive, best‑in‑class total rewards package starting on day one. Competitive PTO package ensuring you have the time off you deserve. Ownership in the company through shared equity, making you a stakeholder in the future of the digital economy. Remote work opportunity anywhere in the world for up to 180 days (subject to restrictions). A career that provides purpose and removes barriers so you love what you do. Equal Opportunity Employment We are an equal opportunity employment organization and pride ourselves on inclusivity, diversity, and the success that comes from diversity. Requests for accommodation during the recruitment process will be addressed confidentially. #J-18808-Ljbffr