Security Engineer

Security Engineer Ledn is a global financial services company built for digital assets. We help Bitcoin holders improve everyday lives while building generational wealth for the future. We offer egalitarian lending, savings and trading products to digital asset holders in over 150 countries worldwide. Our mission is to democratize access to the global economy through digital assets. The 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. The role will drive 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. You will own evolving our authentication layer toward modern, phishing‑resistant approaches and 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. About The Role Application 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 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. 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 (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 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; understanding of software supply chain and Linux internals. Remediate vulnerabilities identified in the penetration test report. 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 Empathy, integrity, collaboration, continuous learning, growth mindset, adaptability, resilience, problem‑solving, curiosity. The Ideal Candidate Will Adaptable, resilient, and comfortable navigating ambiguity in a high‑growth, fast‑paced environment. Builder’s mindset: excited to create, iterate, and scale IS practices. Collaborative partner: influence across functions and cultures with empathy and clarity. Demonstrate integrity and accountability, especially in managing confidential information across diverse legal and cultural contexts. Remote experience and distributed team comfort. A Taste Of What We Provide Comprehensive, best‑in‑class total rewards package that starts on your first day – competitive PTO, shared equity, remote flexibility up to 180 days worldwide, a purpose‑driven career, and the chance to transform the world for the better. Equal Opportunity Statement We are an equal opportunity employment organization and pride ourselves on inclusivity, diversity, and the success that comes from diversity. You may reach out to the Ledn team for accommodation requests throughout all stages of the recruitment process. Requests will be addressed confidentially. Senior Level & Employment Details Seniority level: Mid‑Senior level Employment type: Full‑time Job function: Information Technology Industries: Retail J-18808-Ljbffr

Location: Marília, São Paulo, BR

Posted Date: 11/2/2025