Security Engineer

OverviewSecurity Engineer role at LEDN. Ledn is a global financial services company for digital assets, delivering egalitarian lending, savings and trading products to digital asset holders in over 150 countries. This is a hands-on engineering role focused on application security, identity and access management, and confidential computing to strengthen the security of Ledn's Bitcoin-backed loan platform. The role drives tactical improvements and long-term security strategy for applications and authentication systems. You will work across JavaScript/TypeScript services, AWS serverless stack (Lambda, API Gateway, Cognito, SNS, SQS), MongoDB and Kubernetes microservices, and evolve 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 environments. This is a full-time role with direct impact on product security, infrastructure security and customer trust. 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 solutions (e.g., WebAuthn, passkeys, hardware tokens). Collaborate with Product to align usability, compliance, and security in authentication flows. Define secure session management, device trust, and account recovery approaches. Design enclave-based architectures to isolate and protect sensitive workloads; 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. 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 and Linux internals. Ability to remediate vulnerabilities identified in penetration tests. Strong communication and collaboration skills 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). Experience with user-facing security features such as passwordless authentication, recovery flows, or device trust. Culture & Candidate QualitiesDemonstrates leadership and thrives in startup or tech environments; aligns with Ledn values: integrity, accountability, progress, and empathy. Has a builder mindset, adaptable, resilient, and comfortable navigating ambiguity in a fast-growing setting. Collaborates across functions and cultures with empathy and clarity; maintains confidentiality of sensitive information. Experience working in a remote environment. Benefits & What We ProvideGrowth opportunities and a comprehensive rewards package starting on day one. Competitive PTO and ownership in the company via equity; remote-friendly up to 180 days per year (subject to restrictions). A role with purpose and the opportunity to influence the digital economy. Inclusive, diverse workplace; Ledn is an equal opportunity employer. Accommodation requests are welcome at all stages of the recruitment process and will be handled confidentially. Our team is global and remote-first, with people across North America, Latin America, South Africa and Europe. Due to high application volume, 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 resumes or arrange fees for them. #J-18808-Ljbffr