Security Engineer

Overview 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 around the world. Security is fundamental to protecting our customers and business. This role will drive both tactical improvements and the long-term strategy for securing our applications and authentication systems. You will work across our JavaScript/TypeScript services, AWS serverless stack, MongoDB, and Kubernetes microservices, owning the evolution of our authentication layer toward modern, phishing-resistant approaches. You will also design and operate AWS Nitro Enclaves to protect critical data and cryptographic operations in isolated, verifiable environments. This is a hands-on engineering role with direct impact on product security, infrastructure security, and customer trust. 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 (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 using AWS Nitro Enclaves; integrate 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 with 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 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 and understanding of software supply chain. Deep understanding of Linux internals and remediation of vulnerabilities identified in penetration tests. Strong communication and collaboration skills to influence engineering and product teams. Nice To Have 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 & The Ideal Candidate We’re looking for more than just operational excellence — a leader who thrives in startup or tech environments and embodies our values. Have a passion for progress by being adaptable and resilient; comfortable navigating ambiguity in a high-growth, fast-paced environment. Builder’s mindset, excited to create, iterate, and scale 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 contexts. Experience working in a remote environment. What We Provide Comprehensive, best-in-class total rewards package that starts on your first day. Competitive PTO and ownership in the company through equity. Remote-friendly policy allowing remote work anywhere in the world for up to 180 days (restrictions may apply). A purposeful career and a supportive environment that values inclusivity and diversity. We are an equal opportunity employer and welcome applicants from diverse backgrounds. You may reach out for accommodation requests at any stage of the recruitment process; requests will be handled confidentially. Ledn Working Environment: We are a global, remote-first team spanning North America, Latin America, South Africa, and Europe. 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. We do not accept unsolicited resumes. #J-18808-Ljbffr