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. Our team is diverse and committed to the conviction that digital assets can democratize access to the global economy. Ledn’s core values are: act with integrity always, own it, have a passion for progress, and lead with empathy. Come join us as we build, innovate and revolutionize financial services. This is a full-time Security Engineer role focused on 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 tactical improvements and long-term strategy for securing 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 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; integrate Nitro Enclaves with KMS and secure APIs. Migrate high-value operations into enclave environments; ensure compliance, auditability, and resilience of enclave workloads. 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. Qualifications 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. Strong communication and collaboration skills, able 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). Experience with user-facing security features such as passwordless authentication, recovery flows, or device trust. Culture & The Ideal Candidate Leadership mindset, thrives in startup or tech environments, and embodies Ledn values. Adaptable, resilient, comfortable navigating ambiguity in a high-growth, fast-paced environment. Builder’s mindset to create, iterate, and scale information security practices. Collaborative, able to influence across functions and cultures with empathy and clarity. Integrity and accountability in handling confidential information across diverse contexts. Experience working in a remote environment. Benefits & Why Ledn Growth opportunities within a leading digital asset company. Comprehensive total rewards package and competitive PTO. Ownership in the company through equity; remote work up to 180 days (subject to restrictions). A purpose-driven career and a supportive environment focused on inclusivity and diversity. Location & Application Porto Belo, Santa Catarina, Brazil; Navegantes, Tijucas, Gaspar, Brusque — Brazil (multiple locations cited). We are remote-first and welcome applications from around the world where applicable. No agencies or recruiters, unsolicited resumes not accepted. Due to high 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. You may reach out to the Ledn team for accommodation requests throughout all stages of the recruitment process. Requests will be addressed confidentially. Ledn is an equal opportunity employer focused on inclusivity and diversity. We are a global, remote-first team with employees across North America, Latin America, South Africa and Europe. No blank “job expired” indicators detected in the content; this posting appears current at this time. #J-18808-Ljbffr