Application Security Engineer (m/w/d)

We are looking for an Application Security Engineer to own the end-to-end security posture of our product platform - spanning mobile applications, REST APIs, microservices, cloud infrastructure, and third-party integrations. In this role, the Application Security Engineer will be involved into the product and engineering lifecycle early, shaping secure design decisions before code is written, and validating them through rigorous assessment.

What you will be expected to do

• Own application security responsibility for assigned business functions by performing threat modeling, architecture reviews, penetration testing, secure coding programs, and vulnerability management.
• Perform manual penetration testing and vulnerability assessments on web applications, APIs, and android mobile applications.
• Perform security reviews for AI‐native products, models, pipelines, and inference services.
• Onboard applications into the SSDLC program and be a security point of contact for the application product.
• Own security incident response for product-layer issues, define remediation plans, and track fixes through to closure.
• Integrate and tune SAST/DAST/IAST/SCA tools in CI/CD, create custom rules where needed and actively triage false positives.
• Review and harden cloud infrastructure - Kubernetes RBAC, pod security, network policies, Istio service mesh, Keycloak/OIDC configurations, and IAM across AWS, DigitalOcean, GCP, and Firebase.
• Communicate vulnerabilities and risk clearly to developers, product managers, and leadership - in language that drives actionable results.
• Conduct application security training for engineers, product managers etc.

You might be a strong candidate if you have/are

• Bachelor's degree in Computer Science, Cyber Security, or any related fields.
• At least 2 years of hands-on application security experience, ideally in product‐based or SaaS companies working directly with engineering teams.
• Good understanding of OWASP Top 10, API Security Top 10, and common authorization flaws including BOLA, BFLA, and privilege escalation.
• Experience in manually testing web apps, APIs, and Android apps, manual code reviews (beyond just running tools).
• Familiarity with OAuth2, OIDC, JWT, and typical misconfigurations in providers such as Keycloak and Firebase.
• Experience integrating and tuning SAST/DAST (and optionally SCA/IAST) tools within CI/CD pipelines.
• Exposure to cloud‐native security: Kubernetes, containers, service mesh (Istio mTLS and policies), and IAM concepts across at least one major cloud provider.
• Experience with Cloudflare WAF, perimeter security scanning, and/or red‐team testing is a plus.
• Familiarity with AI/LLM security risks (e.g., OWASP LLM Top 10).
• Practical experience implementing guardrails, prompt validation, output filtering, or other safety controls in production AI features, or assessing insecure use of third‐party AI APIs.
• Ability to script/automate (e.g., Python, Bash) to streamline testing, data collection, and reporting.
• Interest in or experience with building AI based security tools that improve coverage or reduce manual toil.

What Sun King offers

• Professional growth in a dynamic, rapidly expanding, high-social-impact industry
• An open-minded, collaborative culture made up of enthusiastic colleagues who are driven by the challenge of innovation towards profound impact on people and the planet.
• A truly multicultural experience: you will have the chance to work with and learn from people from different geographies, nationalities, and backgrounds.
• Structured, tailored learning and development programs that help you become a better leader, manager, and professional through the Sun King Center for Leadership.