Security Engineer

OverviewLEDN 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. Ledn’s products & services aim to make a difference in the lives and futures of our clients. Our team is diverse and forward-thinking, with a shared conviction that digital assets can democratize access to the global economy. 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 the 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 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. The RoleApplication Security: 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. Authentication & Identity: 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. Confidential Computing (AWS Nitro Enclaves): 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. Additional Security Domains: 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. What You Bring To Ledn10+ years of proven experience in Application Security for 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. 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). Experience on user-facing security features such as passwordless authentication, recovery flows, or device trust. Culture FitWe are seeking a leader who thrives in a startup or tech environment, embodies our values, and is committed to progress, integrity, empathy, and collaboration. We value adaptability, resilience, and the ability to navigate ambiguity in a high-growth, fast-paced environment. The Ideal Candidate WillBe adaptable and resilient, with a builder’s mindset to create, iterate, and scale security practices. Be a collaborative partner who can influence across functions and cultures with empathy and clarity. Demonstrate integrity and accountability, especially in managing confidential information. Be comfortable working in a remote environment. A Taste Of What We ProvideGrowth opportunities in a leading digital asset company. Comprehensive total rewards package starting on day one. Competitive PTO and ownership in the company via equity. Remote-work flexibility, up to 180 days globally (subject to restrictions). A purpose-driven career that aligns with our mission to remove barriers to financial access. We are an equal opportunity employment organization and pride ourselves on inclusivity and diversity. We do not accept unsolicited agency resumes. Location: Flores da Cunha, Rio Grande do Sul, Brazil. We may contact shortlisted candidates and may request a short video response as part of the selection process. #J-18808-Ljbffr