Security Engineer

Overview Join to apply for the Security Engineer role at LEDN 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. 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. The core values are: act with integrity always, own it, have a passion for progress, and lead with empathy. Ledn aims to change the world for the better by building, innovating and revolutionizing financial services. 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. 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. In addition, you will 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 (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 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. Deep understanding of 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 We are looking for a leader who thrives in a startup or tech environment and embodies our values. The ideal candidate will: be adaptable, resilient, able to navigate ambiguity in a high-growth, fast-paced environment; have a builder's mindset; be a collaborative partner across functions; demonstrate integrity and accountability; have worked in a remote environment before. A Taste Of What We Provide Growth opportunities as a leading digital asset company. Comprehensive total rewards package starting on day one. Competitive PTO and remote work flexibility (up to 180 days globally, subject to restrictions). Equity ownership in the company. Remote work from anywhere in the world for up to 180 days (subject to restrictions). A purposeful career with barriers removed so you love what you do. Ledn is an equal opportunity employer; accommodation requests are welcome during all recruitment stages. Contact the Ledn team for accommodations as needed. Ledn Working Environment Ledn is global with a remote-first environment, spanning North America, Latin America, South Africa and Europe. Please note that 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, unsolicited resumes will not be accepted. Seniorities & Job Details Seniority level: Mid-Senior level Employment type: Full-time Job function: Information Technology Industries: Retail Referrals increase your chances of interviewing at LEDN by 2x Sign in to set job alerts for “Security Engineer” roles. Other related roles include Freelance Cybersecurity Engineer with AI/ML Focus, Linux Cryptography and Security Engineer, and Lead Cybersecurity Engineer – Vulnerability Management. Location notes: Contagem, Minas Gerais, Brazil #J-18808-Ljbffr