Staff Application Security Engineer

OverviewStaff Application Security Engineer at Ledn. Ledn is a global financial services company built for digital assets, offering a suite of lending, savings and trading products to digital asset holders in over 150 countries. 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. This is a hands-on engineering role with direct impact on product security, infrastructure security, and customer trust. What You’ll DoLead 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. Remediate vulnerabilities and improve secure development practices in collaboration with engineers. 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). Define secure session management, device trust, and account recovery approaches. Design enclave-based architectures to isolate and protect sensitive workloads using AWS Nitro Enclaves; integrate 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); deploy and operate a SIEM framework with detection rules and incident playbooks; support compliance initiatives (SOC 2, ISO 27001). 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 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 with user-facing security features such as passwordless authentication, recovery flows, or device trust. Culture and FitWe value leadership, adaptability and resilience in a fast-growth environment. Ability to collaborate across functions and cultures with empathy and clarity; operate in a remote-first environment. What We OfferComprehensive, best-in-class total rewards package from day one; competitive PTO and ownership in the company through shared equity. Remote work option for up to 180 days per year (subject to restrictions). A career with purpose and opportunities for growth in a global digital asset company. Equity and remote-work policies are subject to applicable terms. Ledn is an equal opportunity employer and values diversity and inclusion. You may reach out with accommodation requests at any stage of the recruitment process; requests will be addressed confidentially. Location and Application NotesField: Campo Bom, Rio Grande do Sul, Brazil, with global remote options. Please note that due to high application volume, only qualified applicants will be contacted. Shortlisted candidates may be asked to submit a video response or have publicly available social media reviewed as part of the process. No agencies or recruiters, and no unsolicited resumes. #J-18808-Ljbffr